(svn r1727) - Fix: now CmdBuildRailVehicle() behaves correctly if DC_EXEC is set
this commit alters ai.c a little to get rid of the workaround from r1725 so AI players could still build locomotives

(svn r1718) Use the enum TileType as parameter/return type for [GS]etTileType() instead of plain int.
This makes it necessary to rename TileType() to GetTileType() because a type and a function may not share the same name.

(svn r1712) - Fix: a hacked client can no longer send other players trains to a depot

- Feature: [autoreplace] trains now tries to find a depot if they needs to be replaced

Now all 4 types of vehicles goes to a depot if they needs to be replaced

(svn r1696) Use GetTileSlope() instead of FindLandscapeHeightByTile() where it is sufficient. FindLandscapeHeightByTile() uses GetTileSlope() internally and adds some more info, which is discarded in these cases.
While touching the code make a bit more clear how GetBridgeHeight() works.

(svn r1681) -Feature: New realistic acceleration.
This will make things more difficult as narrow curves
and depots impose rather strict speed limits. Feedback welcome
For those who don't like low-speed curves: Switch it off

(svn r1676) Increase the size of TileIndex and TileIndexDiff to 32bits and adapt the save/load data and some other parts of the code to that change

WARNING: If i made any mistake here it WILL lead to corrupted savegames!

(svn r1652) Fix: train and road vehicle lists are now redrawn when vehicles enters/leaves a depot (Hackykid)
fix: the ship status bar was not updated properly after a breakdown if show_speed was off (Hackykid)

(svn r1638) -Fix: Train crashes should no longer desync the game. This is more of a
workaround, as somewhere there might be some InteractiveRandom() abuse
in the code.

(svn r1629) added a counter to tell how many engines you have of each type to the autoreplace vehicle windows and made them show only the vehicles you actually have in the left list.
this also fixes some window updates issues when autoreplacing

(svn r1588) -Fix: [ 1105959 ] coded a workaround in the acceleration code so that
trains don't think they're on a slope while they drive around in a
tunnel

(svn r1565) -Fix: [ 1104969 ] Aircraft in hangar messages are now revalidated before
display
-CodeChange: replaced one if (foo) return true else return false by
return (foo)

(svn r1561) Fix: autoreplacing a singleheaded engine into a dualheaded engine now adds the the rear engine
autoreplacing a dualheaded engine into a singleheaded engine now sells the rear engine
as a sideeffect of this, the price for replacing both engines are now added and displayed once from the depot(instead of two identical numbers written on top of each other, looking like one)
fix: cost for autorenew dualheaded engines were doubled and their value where doubled too

(svn r1558) -Fix: [ 1104350 ] Crashed trains do not initiate the lost vehicle
message anymore

(svn r1554) -Fix: [ 1103187 ] Order Check messages are now validated before
displayed, so that there are no stray error messages any more.
-Feature/Fix: Order Checking is only execute for ONE vehicle in an
order-share system

(svn r1549) Clean up some functions:
uint tile -> TileIndex tile
if () cascade -> switch ()

(svn r1525) -Codechange: rewrote the _order_array, now it can be made dynamic.
-Codechange: renamed all 'schedule' stuff to 'order(list)'
-Codechange: moved all order-stuff to order_cmd.c / order.h
-Codechange: vehicles that share orders are now linked to eachother
with next_shared/prev_shared in Vehicle

Developers: please use AssignOrder to assign data to an order. If not,
you _WILL_ make the save-routine to assert!

(svn r1445) -Fix: reversing a train also reverses the UP and DOWN status for the
realistic acceleration calculation
-Fix: there was a big bug in setting the UP and DOWN flags making it
easy possible for a overloaded train to go up a mountain. This is no
longer possible. They will hang at a certain height

(svn r1407) -Codechange: changed a lot around _stations, _vehicles, _towns and _industries
(in prepare of dynamic arrays):
- DEREF_XXX is changed into GetXXX
- All direct call are directed via GetXXX
- struct Industry has now an index-field
- ENUM'd some stuff
- Replaced home built loops with FOR_ALL_XXX
- Added _stations_size, _vehicles_size, ... which gives the length of the
array (which will be dynamic in the near future)
- Changed lengtof(XXX) to _XXX_size (e.g. _stations_size)
- Removed all endof(XXX) (because mostly it was part of a FOR_ALL_XXX)
- Made the sort-functions of all 4 dynamic
- Made all 4 Initialize functions more of the same
- Some minor tab-fixing and stuff
(tnx to Tron for proof-reading my 100kb patch ;))

Note for all: please do NOT directly call _stations, _vehicles, _towns and
_industries, but use the right wrapper to access them. Thank you.
Ps: please also do not use 'v++', where v is of type Vehicle *.

(svn r1386) Move TileIndexDiff to map.h
Move _tileoffs_by_dir to map.[ch] and encapsulate it in TileOffsByDir()

(svn r1323) Adding autoreplace feature
This feature works much like autorenew, but it will get you a new engine type instead of a new one of the same type. Once
ordered, it will automatically replace the engines while they visits a depot. The GUI for setting this up have been added on the
vehicle overview windows
Note: autorenew is now autoreplace, but to the same engine type
Nice new features, that was added to make this possible
- windows can now have two independant vertical scrollbars
- CMD_SHOW_NO_ERROR have been added as a flag for DoCommandP. It will make it do the action instead of showing the red box with
estimated costs even if shift is pressed
- fixed problem where enginetypes where not initialized when loading a game. It's now done in InitializeGame()

(svn r1288) -Codechange: changed _map2 to an uint16. It is still saved and loaded as
an uint8 till the savegame version is bumped to version 5. Then it works
automaticly as a fully uint16. So _stations[] can not be increased till
after the bump!!

(svn r1283) -Add: AutoRenew is now a client-side patch instead of a game-side patch
Note: this is the first commit that breaks compatibility with 0.3.5!
-Fix: Bufferoverflow with autorenew_money. It is now a 32-bit integer.

(svn r1200) -Fix: Fixed bug pointed out by Tron: when a train is on the
road/rail-crossing, and you let an other train drive towards it, reverse
it, the lights no longer go off.

(svn r1199) -Fix: [ 958098 ] No longer road/rail crossing signals hang when a train
is reversed at the wrong moment (Yeah, our longest open bug finally
fixed :) :) :))

(svn r1198) -Fix: [ 1087701 ] It is no longer possible to crash trains of other
companies by building a depot close to a station. (even more: trains do
no longer enter tiles that do not belong to his owner)

(svn r1015) MFM r789
Replaced the slightly misleading SERVICE_INTERVAL by a function VehicleNeedsService()

(svn r1009) -Feature: per-station vehicle lists
This adds a little button per vehicle class to the station window which opens a list of all vehicles that have this station on their schedule.
As side effect this gets rid of some global variables.

(svn r955) Replace uint16 for orders with struct Order
This adds no functionality, but is a stepping stone for future improvement (like 16bit order indices) and is easier to read.
This changes preserves binary compatibility wrt savegames.

(svn r925) Use sound enums
Also play the correct sound when a toyland road vehicle breaks down

(svn r901) Small step in the process to clean up the DPARAM mess:
- reduce to 2 sizes (*DParam64 for 64bit values, *DParam for the rest)
- use inline functions instead of macros
- add assert()s to check for buffer overruns

(svn r815) Include strings.h only in the files which need it.
This should reduce the compile time after altering english.txt by about 1/3, because "only" 62 instead of 90 .c files must be recompiled.

(svn r607) -Patch: [ 985102 ] static cleanup
Thanks to lvoge

(svn r513) Merge revisions 402, 416, 417, 478, 479, 511, 512 from map to trunk
This includes 2 fixes
-Fix: [1048596] Monorail and Maglev sounds are swapped (r511)
-Add special case to load the jackhammer sound (r478)
The rest are cleanups und enumeration to make merging possible/easier

(svn r294) -Fix: autorail always builds rail, instead of occasional rail removal (on pressing hotkey after pressing 'bulldozer')
-Fix: network fixes (Tron)
-Some textfile changes, mainly URL's

(svn r167) -Fix: [972247] bug in '[a] weird non-uniform stations handling'
(blathijs)

(svn r165) -Feature: Option to sort vehicles in vehicle-list window by different criteria. Total independent sort for all types and players. Periodic resort of list every 10 TTD days. Thank you for your graphical inspiration follow and buxo (since none of you provided any code).
-Fix: Sorter icon pointing down 'v' sorts in every window lowest value first, '^' highest value first
-CodeChange: move Dropdownlist from settings_gui.c to widget.c. More in place there.

(svn r160) -Codechange: made GetTileTrackStatus more readable (blathijs)
-Fix: some minor fixes around GetTileTrackStatus (blathijs)

(svn r77) -Fix: [1010788] AI service interval bug (tnx truesatan)
-Add: AI overrides service interval to 180 days
-Fix: AI hanged when all vehicles were disabled in Patch menu