(svn r2560) Fix: various minor code changes.
Added RandomTile/RandomTileSeed functions to generate a random tile.
Changed landscape routines so they don't assume that the Y map side is a power of two. (support for this is not complete, though)
Changed some frequently used map macros to not compute the values each time.
Silence some warnings on MSVC.

(svn r2419) - Fix: saving no longer changes your cursor if it is in a non-mouse state.
- Fix: autosaving/loading; it no longer returns a fail code when saving is already in progress. In the case of a load, the game pauses to wait for the save to finish. (glx)
- Fix (regression): fix a bug in the 'buggy load' code where a wrong offset was used for the LZO format.

(svn r2391) - Feature: saving games happen in a seperate thread so you no longer will have to wait such a long time (especially handy on bigger maps and multiplayer games). The mouse also changes into the 'ZZZ' state :P. The thread on windows is currently given a little-bit-less-than-normal priority so it should not interfere that much with the gameplay; it will take a bit longer though. Upon the exit of the game any pending saves are waited upon.
- Fix: fixed GetSavegameFormat() so that it takes the best compressor (highest), or a forced one added with the parameter
- Open issues:
1. Don't attempt to load a game while saving is in progress, it will kick you back to the intro-screen with only the vast ocean to look at.
2. The server is disabled from threaded-saving, but might be enabled in the future.
3. Current implementation only allows 1 additional running thread.
4. Stupid global variables.....grrr
Big thanks for TrueLight and the amazing memorypool :D

(svn r2387) - CodeChange: made the saveload code more readable and also removed the 'byte' saveload arrays which means you can save an array of more than 255 elements, or bigger structs than 255 bytes. This doesn't yet solve the problem that a chunk can be a maximum of 16384 big.
- Fix: also fix an unnoticed error in SlSaveLoadConv() due to wrong types.

(svn r2080) - Fix: [OldAI] p->ai.state_counter was uint16 but could hold a tile index, therefore overflowing - changed that to uint32 and bumped the savegame revision to 32. It *MIGHT* close bug 1151374 - it certainly caused AI to stop building anything sometimes.
- While at it, use TileIndex as the tile index type in AiRemovePlayerRailOrRoad() and AiStateRemoveTrack().
- Make the number of tiles scanned 4*MapSizeX() instead of 1000. It *MIGHT* close bug 1116614.

(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 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 r1768) -Codechange: Store town index in _map2 of town tiles
Moved house type from _map2 to _map3_hi for MP_HOUSE
Moved foundation and roadworks from _map2 to _map3 for
MP_STREET
This increases game speed by a factor of around 15(!) if many cities are around.
Converting an old game is done automagically, but can take a while

(svn r1764) -Add: dynamic towns, you can now have up to 64k towns (let me know when
you have that amount of towns in a map ;))

(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 r1673) - Codechange: Removed some redundant comments from r1667
Saving the player color for signs will work right after the savegame bump

(svn r1667) - Feature: Signs are now shown in the color of the player who created them
(Note: The player information is currently not stored in savegames. Upon loading a game the signs will all be gray again)

(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 r1440) -Feature: Allows more flexible airport layouts now, as the number of
terminals in every group can be freely chosen
-Codechange: AT_OILRIG is now 15, so that new airports can be added
easily.

(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 r1417) Fix: The invisible tiles on the southern border are now converted to class MP_VOID when an old map (with wrong classified invisible tiles) is loaded.
I bumped the minor savegame version for that, even though it's not really necessary. We're not gonna run out of minor savegame versions anyway though. ;)

(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 r1248) -Add: initial OS/2 support (read docs/ReadMe_OS2.txt) (orudge)
Works fine, beside some minor stuff:
- Network is not working yet
- Keyboard is not working
- No MIDI support
- 'A few file selector bugs involving drives'

(svn r1082) Feature: Chat toolbar
- to chat with all players press Return (or Shift-T) and type in the message
- Press Return again to send the message

(svn r1076) Feature: Patch setting to autosave the game on exit
If you set autosave_on_exit = true in openttd.cfg, your game will be saved as exit.sav in the autosave folder and you won't be asked if you want to quit the game any more.

(svn r907) Sprinkle holy ANSI water:
- "inline" must before the return type (and after "static")
- Initialise all struct members, not just some of them
- Remove (one) spurious semicolon

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

(svn r223) -Fix: Const correctness and miscellaneous fixes. Thank you Tron for your diligent fixing of warnings (and some possibly bugs) (Tron)
-CodeLayout: Remove trailing spaces and Windows linebreaks

(svn r122) Change: exclusive transport rights are now stored per town instead of per station
Exclusive rights from old savegames will be reset.