(svn r2516) - Feature: [pbs] Implement path-based-signalling. This allows multiple trains within the same signal block, provided their paths dont intersect. For this the block must have all exit and entry signals be pbs signals. Place these by ctrl-clicking 4 times on a normal signal.
- Feature: [pbs] Implement autoplacement of pbs blocks, when a block has an entry and an exit pbs signal, covert the entire block to pbs. Can be turned off in the patch settings.
- Feature: [pbs] Allow showing of reserved status by making the tracks darker, when the pbs debug level is at least 1.

(svn r2450) * Codechange: Replaced all uses of the arrays in tile.h with calls to the associated wrapper functions.
* Codechange: Made npf.c use some map array accessing wrappers instead of direct access.
* Codechange/Fix: Named every enum in tile.h. Fixes a nasty bug on MSVC where arrays would be initialised with zeroes (tnx Asterix_)
* Removed magic numbers from tables in tile.c.
* Added some explicit casts in tile.h.

(svn r2428) - Feature: [newgrf] Implement shorter train vehicles (Therax), and the callback that goes with it.
- Codechange: Remove some magic numbers (PALETTE_CRASH)

(svn r2411) - Codechange: Have trains cache stuff like consist power/weight/max speed instead of recalculating it each time.
- Fix: Station ratings now depends on the max speed of a consist, without being affected by other speed limits from realistic acceleration.

(svn r2308) - Fix: enforce server-only and/or offline commands by giving them flags in the process table. This also fixes bug "[ 1190944 ] Many commands not checked for security"
- CodeChange: move ValParamRailtype() to check rail type from command.h to vehicle.h where it is better suited.

(svn r2300) - CodeChange: check the last number of commands, now only the refit ones remain, and some server-only commands.
- CodeChange: remove cmd-misuses CmdStartScenario() and CmdDestroyCompanyHQ()
- Fix (invisible): when parameter checking CmdRestoreOrderIndex() the vehicle did not have its orders yet, so it would fail. So move doing this until AFTER the orders have been added back in RestoreVehicleOrders()

(svn r2290) - CodeChange: protect the next batch of commands. This brings us to a total of 61, which is 53% :)
- CodeChange: To correctly accept engine-prototypes, the best-player checking has been moved to its own function, I hope it functions the same as before.
- CodeChange: Added symbolic types of PlayerID, OrderID and EngineID. For engines also added GetEngine() and IsEngineIndex(), similar to the other such functions.
- CodeChange: To correctly build industries, some tables have been moved to build_industry.h. The only way to find out currently if an industry is valid in a climate is by looping all industries and checking if it matches. Also to comply with the patch setting build_rawmaterial_industries, it is assumed that these industries do not accept any cargo of any type. This can and probably should changed in the future to some flag in their struct. Also use _opt_ptr instead of _opt.
- CodeChange: implemented the HQ checking code inspired by MarkR2 in "[ 1190944 ] Many commands not checked for security". Unfortunately it is impossible to prevent only deleting a HQ by a modified client atm.
- CodeChange: For insert order and modify order their parameters are implicitely truncated to 8 bits, instead of the 16 bits said in the comments.

(svn r2256) - Fix: Trains cannot find a depot when they are in a tunnel. (glx)
- Add: GetVehicleTrackdir() helper function.
- Codechange: Moved SortStruct from vehicle_gui.h to ttd.h, so the dependency from vehicle.h on vehicle_gui.h could be removed.
- Codechange: Typedeffed the VehicleTypes struct so it can be used as the type for Vehicle.type instead of "byte".
- Codechange: Removed prototype for VehicleSorter(), which had no implementation anymore and was never called.

(svn r2046) -Codechange: moved all waypoint code to waypoint.c/waypoint.h
-Codechange: rewrote some functions while moving waypoint-stuff
-Add: added support for 64k waypoints
-Fix: made the waypoint struct a bit more logic (no bit-fucking)

(svn r2024) -Fix: [autoreplace] reverted all changes involving v->set_for_replacement as they caused desyncs.

The bad sideeffect of this is that now no vehicle will automatically go to a depot anymore just
because it is set to be autoreplaced. We will have to find a better way to solve this problem.

Revisions reverted: 1640, 1707, 1709, 1710, 1712(but not the cheat prevention in this one)

(svn r1863) Give the effect vehicle type enums more descriptive names and use the enum as parameter type for CreateEffectVehicle*()
-Fix: [1116619] Generate the correct smoke type for diesel trains

(svn r1834) - Fix: NPF does not check the owner of its target, busses try to enter other players' depots. TODO
- Add: asserts to find the v->u.rail.track == 0 problem.
- Add: IsValidDepot(), IsValidTown(), IsValidSign(), IsValidVehicle(), IsValidStation()
- Add: GetTileOwner(), IsTileOwner()
- Codechange: Replaced IsShipDepotTile(), IsTrainDepotTile(), IsRoadDepotTile() by IsTileDepotType().
- Codechange: typedeffed the MAP_OWNERS as Owner. Should be used as variable type.
- Codechange: Replaced a few uint by TileIndex.

(svn r1817) -Codechange: Moved depot-functions to depot.c
-Codechange: Added wrappers around depot-access (GetDepot no exists)
-Codechange: Made depot-functions a bit more logic (no longer
GetDepotByTile crashes your game when you request it on a non-depot tile)
-Add: made depots dynamic (yes, 64k depots are possible now)

(svn r1786) -Fix: unitnumber is increased to 16bit, so now you can have up to 5000
trains in one game (instead of the 240 which was the current value).
Default max allowed vehicles per type is changed:
Trains: 500 (old 80)
Road: 500 (old 80)
Ships: 200 (old 40)
Aicraft: 300 (old 50)
(Tnx to Celestar and Darkvater for checking the patch)

(svn r1770) -Fix: Hopefully last pieces of code that are containing a station-id
(and should be an uint16, not uint8)

(svn r1741) - Fix: added IsVehicleIndex() so it's possible to protect GetVehicle() from reading an invalid vehicle index
- Fix: added check for v->type in some commands, which expects v to be a specific type

Checks like this is needed to protect network servers from people, who hack their clients to either cheat or crash the server

NOTE: if I made a mistake here it can make a function unreachable when it should be used. Here is one place to look if something weird happens

(svn r1721) -Feature: It is now possible to build multiple road stations (up to 8) on
a single station.
Thanks to: Truelight for the saveload code, Darkvater and Hackykid for
network testing and Tron for proof-reading 1500 lines of diff.

(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 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 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 r1521) -Fix: Ship Vehicle Lists are now redrawn correctly
-Codechange: added some const to last commit
-Codechange: Ship and Aircraft lists are now update on order change, not
on new day

(svn r1448) -Fix: The current_order of a vehicle is now correctly saved (caused
massive desyncs)
Warning: savegames which are made with the nightly of 08-01-2005 will
NO LONGER work!!

(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 r1429) Change: bumped savegame to revision 5.
- Now orders are bigger
- Now _map2 is official 16 bits

(svn r1426) -Codechange: cleaned up the reference code in the saveload routines
-Codechange: removed next_in_chain_old, and saved ->next for Vehicles
(and bumped savegame revision for that to version 4.4)
-Codechange: Added _sl.full_version, which has both major and minor version

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

(svn r990) Fix a display bug in the order list:
TTD stores invalid orders different than OTTD, this resulted in empty lines in the order list. With the overhaul of the order system this got worse: no line was shown at all.
Fix this by sanity checking while loading and convert the orders accordingly.

(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 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.