(svn r7565) -Codechange: Rework DEBUG functionality. Look for appropiate debugging levels to
use in debug.h. grfmsg() is now used as a specific debug-function for grf.

(svn r7386) -Codechange r7385: moved deletion of the vehicle highlight from DeleteVehicle to the sell commands as they are not called as often
Also added a return to the window loop prevent looking at the rest of the windows once the right depot window is found

(svn r7330) -Fix (r7304): Data invalidation doesn't always happen as the local
player, resulting in an empty vehicle purchase list. Specify the player
as an argument to IsEngineBuildable()

(svn r7313) -Codechange: Calling invalidate data on a window will surely warrant a redraw, so call
that after the WE_INVALIDATE_DATA event and remove (some of) the superflouous calls.

(svn r7032) - Fix (r1704): Sprite index wasn't updated with correct image number if
custom image lookup fails.

(svn r6994) -Regression (r6291): When sending an aircrafts to a hangar the wrong bit gets tested to determine if a aircraft should stop there or just get serviced
Also remove a stale comment
Both spotted and fixed by Mart3p

(svn r6771) -Codechange: Replace two macros with functions. IS_HUMAN_PLAYER and
IS_INTERACTIVE_PLAYER

(svn r6769) -Codechange: Minor syntax, const correctness, variable localization, coding
style changes to airport code, and cleanup of airport.c. Should not change
any functionality.

(svn r6768) -Cleanup: For airports change *Airport to *apc (variable naming coding style
conformance (AirportFTAClass), *FA to *apFA (to better reflect its type
AirportFTAbuildup), and ->next_in_chain into ->next.

(svn r6651) -Coding feature: added the windowevent WE_INVALIDATE_DATA
This gives the ability to invalidate some window data and recalculate as needed instead of doing it for each WE_PAINT

This event is called right away when using InvalidateWindowData(), so it may be a good idea to set a bool or similar in the window
or similar and then act on that bool in WE_PAINT instead of doing a lot of stuff in WE_INVALIDATE_DATA as it might be called more than once before WE_PAINT is called

InvalidateWindowData() will not automatically repaint the window, so if you want to repaint it as well, you need to mark it dirty as well.

Made the depot windows use WE_INVALIDATE_DATA to set when to generate the engine and wagon lists instead of at each redraw
It makes no sense to regenerate the list when say using the scrollbar if we know that no vehicle have entered or left the list

NOTE: currently there is a piece of code to generate the list when it's not needed and compare it to the stored list and assert if they mismatch
This check is somewhat slow and kills the whole idea of WE_INVALIDATE_DATA, so it's a short lived one to verify that InvalidateWindowData() is used everywhere where it's needed

(svn r6644) -Fix(r6637): remove inline to allow MSVC compilation
-Fix(r5124): Add aircraft.h to MSVC projects

(svn r6637) -Codechange: merged all (vehicle type)EnterDepot into VehicleEnterDepot()
This revealed duplicated code like aircraft lists got invalidated twice
Moved invalidation of the vehicle detail window to VehicleServiceInDepot() as it should always be updated when serviced

(svn r6624) -Feature: added ability to add refit commands to vehicle orders (can only be done in goto depot orders)
Example: make a train transport iron ore from A to B, then it visits a depot and refits to steel
It then transport steel back to A or near A if there is a factory and then it visits another depot to refit to iron ore again

This is controlled in the orders. If a goto depot order is lightlighted, then "Unload" changes to "Refit"
Control click "Refit" removes the refit part of the order (as the tooltip says)
The player will still pay the normal refit costs

Known issues:
If a vehicle is not in a depot, then the refit window will fail to tell refitted cargo capacity
Refit costs in the refit window can sometimes print 0 when it should not because the refit calculation is unaware that the vehicle will be refitted in between

Warning: autoreplace got a protection against replacing something so you get a new cargo type, but it can fail here. In the iron ore/steel example, it can see that
the vehicle carries iron ore and the new one can be refitted to iron ore, then it will replace. It will not check to see that it's valid for steel as well.
This is something to look into in the future

(svn r6424) -Codechange: [autoreplace] removed a loop though all vehicles from each time the window is redrawn
To do this, the player struct contains an array, that contains the count of each engine type that the player owns
Those arrays are updated each time a vehicle is build or deleted and is calculated on load (it's not saved)
It's possible to access the arrays outside of the autoreplace GUI, so feel free to read from them in other patches as well

(svn r6381) -Cleanup: make the '/* */' comments that span multiple lines more uniform.
-Cleanup: whitespace alignment of a few tables.

(svn r6376) -Codechange: [vehicle refit] moved all refit cost calculations into GetRefitCost()
Now it's possible to tell refit costs for an EngineID without actually having build a vehicle

(svn r6356) -Fix: FS#263 planes come out of hangar and drive back into hangar
Now all vehicles are serviced when it's time for service and they are in a depot
This will avoid the goto depot order from ever showing up when in a depot

(svn r6353) -Codechange: Make DestinationID a typedef of uin16, which is as large as any type of destinataion (StationID, DepotID, WaypointID) it can hold
DestinationID being a union of these types is just hassle without benefit and cannot be handled correctly everywhere because of local lack of information

(svn r6352) -Fix: FS#322 Send to depot bug
now vehicles can't be sent to a depot when they are already inside a depot
before they would remember the order and try to turn around when leaving the depot

(svn r6291) -Feature: Vehicle lists from the station window now also got the goto depot button
-Codechange: unified the code for mass goto depot to avoid duplicated code
-Fix: Vehicles already on the way to depots will not be cancelled by mass goto depot (made it really hard to send all vehicles at once)

(svn r6246) -Feature: added the many times requested "send all vehicle to depot" button
it's located in the vehicle list screen and does the same as in the shared orders window (send all vehicles in list to a depot)
it will still not inform the player if a vehicle failed to find a depot, so don't take for granted that all of them go

(svn r6229) -Feature: Shared order lists now got a "goto depot" button
this will try to send all vehicles in the list to depots/hangars
currently if one fails to find a depot, it will not tell the player

(svn r6165) -Feature: control click Goto Depot will now make the vehicle service
at the depot and leave right away.
To tell the difference the status of stopping vehicles will be in red,
while servicing vehicles will be green.
-Codechange: remove some dead code in CmdSendAircraftToHangar() since it is
conflicting with new functionality. Now p2 means the same for all types

(svn r6142) -Codechange: added WaypointID (sorry DV, couldn't splits it anymore)
-Codechange: introduced DestinationID, which is in fact an union of several types
Used in Order struct, so no longer StationID is abused for all targets.
Hangars are a big exception, as they use a station-id with GOTO_DEPOT (go figure)

(svn r6053) -Codechange: renamed all IsXXXIndex to IsValidXXXID
-Codechange: IsValidXXXID now also checks if XXX is really valid, not if the number is within range
Both changes again in preperation of the new mem-pool system, which requires this.
IsValidXXXID is not a bit less pretty, but that will be cleaned up after the new mem-pool system

(svn r6052) -Codechange: change OrderType (order->type) in a typedef
-Codechange: renamed DeleteDestinationFromVehicleOrder to RemoveOrderFromAllVehicles to reflect his function better
-Codechange: changed the params of RemoveOrderFromAllVehicles, to avoid unneeded variable-creation

(svn r6047) -Codechange: FOR_ALL now _only_ loops valid items, and skips invalid ones
-Codechange: use IsValidXXX where ever possible
Note: both changes to prepare for new pool system, which needs those changes.
For every pool there are 2 ugly lines, which will be removed when done
implementing new pool system.
Based on FS#13 by blathijs, partly implemented.

(svn r6039) -Fix: [newGRF] FS#287 Bugfix for error in NewGRF callback 31 code for aircraft (Mart3p)
introduced in rev 5822

(svn r5926) -Codechange: make _cur_year contain the full year, instead of the offset since 1920
-Codechange: store all year related variables that are _not_ stored in a savegame/transported over the network in the same format as _cur_year

(svn r5887) -Cleanup: move date related functions, defines and variables to date.[ch]
-Cleanup: fix whitespace related coding style issues in date.[ch]
-Cleanup: make original comments doxygen compatible and remove/change outdated comments

(svn r5594) Be more strict what's allowed to be built in a hangar: if the airport can't handle planes/helicopters don't present and disallow building planes/helicopters - the latter case wasn't covered yet.
Also remove an error message about building aircraft which can't be triggered by a normal client

(svn r5454) -Fix: [ 1394231 ] Autorenew glitch on helicopters
[ 1459348 ] Helicopters (possibly other aircraft) stopping in depot...
by committing FS#233 Bugfix for autorenewed/autoreplaced helicopters staying in depot (Mart3p)
now helicopters (this only applied to helicopters) no longer stops in hangars when replaced and they will not even go there for autorenew if the model is out of date

(svn r5346) - Feature: Add 4 new airports. 2 for aircraft, 2 for helicopters.
Commuter airport: Small. 5x4. 3 terminals, 2 helipads.
Intercontinental: massive. 9x11. 8 terminals, 2 helipads, 4 runways.
Helidepot: a small heliport with a depot for helis only.
Helistation: a large heliport with 3 helipads and a depot.

(svn r5124) Add IsAircraftInHangar{Stopped,}(), which supersedes CheckStoppedInHangar()
-Fix: Be more strict what it means for an aircraft to be in a hangar: It's not just being stopped on a hangar tile

(svn r4826) -Fix: [autoreplace] fixed possible problem when autoreplacing and was number of vehicles (of a type, not total) was reached
now the new vehicle gets the same number as the old one, completely removing the problem where we could run out of numbers
since we don't have to find free numbers for the new vehicles, autoreplace should be somewhat faster, specially in late games
NOTE: in CmdBuildRailVehicle(), bit 0 and 1 in p2 have been switched to make the meaning of bit 0 consistent with the other build commands. CmdCloneVehicle() is modified to follow this as well

(svn r4342) Change the first two parameters of commands - virtual pixel coordinates of the tile to operate on - to a TileIndex
Remove DoCommandByTile(), because now it does the same as DoCommand()

(svn r3757) -Feature: Delete news items about vehicles, when they get stale
This is used to delete
- all news about a vehicle, when it gets deleted
- "vehicle has stopped in depot" news, when it gets started
- "vehicle has invalid orders" news, when the orders get changed

(svn r3564) Several smaller changes:
- Don't treat non-booleans as booleans
- Reduce variable scope
- Bracing
- Use DeMorgan's law to make conditionals easier to read
- if cascade -> switch
- Replace some magic numbers by symbolic names
- Avoid assignments within other statements

(svn r3396) - Autoreplace changes:
- Change fixed array per player to a single pool. This avoids future problems
with vehicle numbers and decreases savegame size. Engine replacements from
previous savegames will be lost.
- Move engine replacement code from players.c to engine.c.
(thanks to blathijs for rewriting this)

(svn r3367) Unify the 4 distinct CMD_CHANGE_{AIRCRAFT,ROADVEH,SHIP,TRAIN}_SERVICE_INT commands into one CMD_CHANGE_SERVICE_INT command.
As side effect this is a
-Fix: The default AI tried to change the service intervals of vehicles via the CMD_CHANGE_TRAIN_SERVICE_INT command - regardless of the type of the vehicle - which of course failed for non-trains

(svn r3181) -Bracing
-Indentation
-Whitespace
-DeMorgan's Law
-Test with NULL or 0 for non-booleans
-'\0' instead of 0 for chars
-Remove redundantly redundant comments (like DoFoo(); // Do foo)
-Join multiple short lines with a single statement
-Split single lines with multiple statements
-Avoid assignments in if

(svn r3156) -Fix: removed some cases where autoreplace windows were redrawn when nothing was changed
due to the FOR_ALL_VEHICLES(), redrawing those windows are slow

(svn r3138) -Fix: [clone vehicles] fixed assert when it was possible to allocate some vehicles to clone a train, but not for all cars
Now it gives "too many vehicles" error message instead
To make this work, AllocateVehicles() needed to be moved to vehicle.c (from aircraft_cmd.c) and made non-static

(svn r3111) -Fix: [autoreplace] [ 1341783 ] Assertion failure in vehicle.c line 378
running MaybeReplaceVehicle() is now delayed until after the loop in CallVehicleTicks()
This avoids selling the vehicle the loop currently works with (and continues to work with afterwards)