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

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

(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 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 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 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 r5916) -Cleanup: use MIN_YEAR/MAX_YEAR for the year boundaries and BASE_YEAR when comparing _cur_year with a 'full' year.
-Cleanup: replace some magic '1920' values with BASE_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-Cleanup: make original comments doxygen compatible and remove/change outdated comments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 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 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 r3210) -Codechange: use IsRailWaypoint where possible (instead of magicnumbers)
-Codechange: IsRailWaypoint should take 'tile', not 'm5'

(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 r3179) - RandomRange() and RandomTile() instead of home brewed versions
- CHANCE*() instead of mumbling strange numbers

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

(svn r1545) Add TileHeight() which returns the height (not multiplied by 8)
Replace some direct references to _map_type_and_height with TileHeight()/IsTileType()

(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 r1346) -Fix: fix signed/unsigned warnings
-Fix: latent removal of 2 lines from ttd.c which I forgot because the file was not saved :O

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