(svn r6776) -Codechange: Use IsValidPlayer() function to determine of a PlayerID is an
actual playable player (< MAX_PLAYERS) or not.

(svn r6406) -Codechange: Rename TileOffsByDir to TileOffsByDiagDir because it accepts
DiagDirections, and add TileOffsByDir that handles Directions.
-Codechange: Make the treeloop use TileOffsByDir().

(svn r5946) -Add: merged the TGP branch to mainline. TGP adds:
- New optional landscape generator (TerraGenesis Perlin)
- Load heightmaps (either BMP or PNG)
- Progress dialog while generating worlds (no longer a 'hanging' screen)
- New dialogs for NewGame, Create Scenario and Play Heightmap
- Easier to configure your landscape
- More things to configure (tree-placer, ..)
- Speedup of world generation
- New console command 'restart': restart the map EXACTLY as it was when you
first started it (needs a game made after or with this commit)
- New console command 'getseed': get the seed of your map and share it with
others (of course only works with generated maps)
- Many new, world generation related, things
- Many internal cleanups and rewrites
Many tnx to those people who helped making this:
Belugas, DaleStan, glx, KUDr, RichK67, Rubidium, and TrueLight (alfabetic)
Many tnx to those who helped testing:
Arnau, Bjarni, and tokai (alfabetic)
And to all other people who helped testing and sending comments / bugs
Stats: 673 lines changed, 3534 new lines, 79 new strings

(svn r5070) Merged the bridge branch
-Feature: Bridges can now be placed above:
Any railway track combination (excluding depots and waypoints)
Any road combination (excluding depots)
Clear tiles (duh), including fields
Tunnel entrances
Bridge heads

Thanks to Tron for idea and implementation, KUDr for the yapf synchronization and many others for hours of testing

There are still a number of visual problems remaining, especially when electric railways are on or under the bridge.
DO NOT REPORT THOSE BUGS FOR THE TIME BEING please.

(svn r4572) Remove vehicle_leave_tile_proc
There's exactly one implemented function (unbarring a level crossing) and one place where it can be triggered (a train leaves a level crossing)
It's a bit overkill, so just handle this one case where it can happen

(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 r3556) Add accessors for handling tree tiles
See tree.h for details

(svn r3514) -Codechange: Replace direct fiddling of bits for the ground type and density of clear tiles with symbolic names and accessors.
See clear.h for details

(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 r3077) static, const, bracing, indentation, 0 -> '\0'/NULL, typos in comments, excess empty lines, minor other changes
nothing spectacular, just some stuff, which piled up

(svn r2962) - const correctness for all Get* functions and most Draw* functions that don't change their pointer parameters
- change a lot of byte player types to PlayerID
- beautify header files, same "#endif /* filename */" ending

(svn r2595) -Codechange: Introduced "IsSteepTileh" to find whether a tile is steep
(i.e. spans two height levels) and use it throughout the code.
-Codechange: Add CanBuildDepotByTileh to find if a tile is suitable to
build a depot on it. Wraps some bitmagic which seems quite unreadable at
first glance

(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 r2288) - CodeChange: protected the next batch of commands (41 so far, out of 115).
- CodeChange: changed the airport gui airport-type checking. Added function GetValidAirports() that returns bitmasked availibility, is also used for checking.
- CodeChange: to check tree-planting, 2 const arrays have been moved to table/tree_land.h (type and count)
- CodeChange: added IsTownIndex() in following of IsStationIndex(), etc.
- Fix (regression): road tunnels did not work anymore, forgot that their type was 0x200 (documented now)

(svn r1790) Make CmdPlantTree() and related functions more safe and (hopefully) more readable:
- check if end tile is on the map
- uint -> TileIndex
- if cascades -> switch

(svn r1706) Implement ScaleByMapSize() and ScaleByMapSize1D()
These scale a number relative to the map size/circumference.
Use them to scale the amount of map objects.
Of course at the moment they return just the input, because there are no bigger/smaller maps yet.

(svn r1560) Introduce SetTileType() and SetTileHeight()
Replace direct references to _map_type_and_height with these

(svn r1486) -Codechange: moved all 'signs' stuff to signs.c/h and prepared it for
dynamic arrays

(svn r1299) -Fix: [ 1092473 ] In SE, when trees are placed randomly, they are no
longer placed on farmland

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

(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 r787) Invert the sense of the DO_TRANS_BUILDINGS flag to be consistent with its own name and all other DO_* flags.
Now it is active-true.

(svn r724) Remove restriction that a tile can only accept 3 cargo types.
This especially enables houses to accept passengers, mail, goods AND food.
Add string templates for up to 5 cargo types for the tile info window. If more are needed just add them.
Simplify (de-uglify) the logic for cargo acceptence for houses and split the goods/food table into two. The acceptance is unmodified, but accepting goods AND food is now trivially possible. The exact amounts have to be decided.
This is based on Celestar's changes in the map branch plus some further bits that will be merged there soon.

(svn r604) -Fix: [ 999669 ] Wrong trees (toyland's) in sub-tropical landscape style
Tree generation code sometimes set the non-existent growth state 7
This could also become manifest in snow covered trees below the swnow line in arctic climate and similar effects

(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