(svn r7565) -Codechange: Rework DEBUG functionality. Look for appropiate debugging levels to
use in debug.h. grfmsg() is now used as a specific debug-function for grf.

(svn r7331) - Codechange: Rename all memory pool macro's and types to "old pool", so the new pool implementation can be committed alongside it.
- Codechange: Rename pool.[ch] to oldpool.[ch].

(svn r7330) -Fix (r7304): Data invalidation doesn't always happen as the local
player, resulting in an empty vehicle purchase list. Specify the player
as an argument to IsEngineBuildable()

(svn r6774) -Codechange: Rename the badly named OWNER_SPECTATOR to PLAYER_SPECTATOR and
put it into player.h where it belongs (instead of map.h)

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

(svn r6714) -Codechange: replaced a direct manipulation of windows with InvalidateWindowData() in rail_cmd.c
Moved the actual modification of railtype to WE_INVALIDATE_DATA in the train depot handler
-Codechange: added SetWindowDirty() to WE_INVALIDATE_DATA as it made no sense to update the list without making the window dirty

(svn r6681) -Fix: when vehicles never expire they will stay at peak reliability instead of the lowest to make them useful even when old
-Fix: when retiring an engine design, invalidate the build windows and invalidate the build window data
-Fix: mark build windows dirty when engine reliability changes

(svn r6381) -Cleanup: make the '/* */' comments that span multiple lines more uniform.
-Cleanup: whitespace alignment of a few tables.

(svn r6137) -Codechange: some very minor cleanups:
- Start using DeleteXXX for every pool item, not manually doing it
- Use some wrapper to improve logic
- Rewrote some pieces to improve logic

(svn r6049) -Codechange: forgot EngineRenew in r6047
-Codechange: cleaned up the EngineRenew code a bit (coding style mostly)
-Codechange: forgot the correct comment in station_cmd
-Codechange: move pool-stuff to engine.h, like we always do

(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 r5999) -Feature: change the original date format to a 32 bits format based at the year 0.
The game date subsystem now allows someone to start in the year 0 and continue
up to the year 5 000 000. However, you currently cannot build anything before
1920 as there is no newgrf support for dates before 1920 or after 2090 yet.

(svn r5975) -Cleanup: use ORIGINAL_BASE_YEAR & ORIGINAL_MAX_YEAR where the functions really depend on the original date format.
-Cleanup: use DAYS_TILL_ORIGINAL_BASE_YEAR where the date variables are in the old date format and conversions are needed.
-Cleanup: replace one (forgotten) instance of uint16 with Date.

(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 r5934) -Cleanup: forgot some conversions to Year and to Date
-Cleanup: use _cur_year instead of _date for some (year based) comparisons
-Cleanup: remove a magic number in favour of another (less) magic number

(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 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 r4902) Newgrf : Introduction of the newgrf_cargo files.
Clearing engine and newgrf_engine from cargo related structures.
Apart from moving stuff cargo related, there is nothing really newcargo for now.

(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 r3895) - Add proper SLE(G)_CONDNULL macros for the empty space reservation in savegames and update where used
- Also add this capability to settings

(svn r3396) - Autoreplace changes:
- Change fixed array per player to a single pool. This avoids future problems
with vehicle numbers and decreases savegame size. Engine replacements from
previous savegames will be lost.
- Move engine replacement code from players.c to engine.c.
(thanks to blathijs for rewriting this)

(svn r3378) - NewGRF Fix: Use order status to determine whether a vehicle is loading instead
of speed, and get that state from first vehicle in a train consist.

(svn r3308) BAD
foo.h: int bar;

GOOD
foo.h: extern int bar;
foo.c: int bar;

(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 r3111) -Fix: [autoreplace] [ 1341783 ] Assertion failure in vehicle.c line 378
running MaybeReplaceVehicle() is now delayed until after the loop in CallVehicleTicks()
This avoids selling the vehicle the loop currently works with (and continues to work with afterwards)

(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 r2657) -Codechange: The available railtypes per player are now a bitmask, so
that railtypes do not be in ascending order of appearance. Allows easier
implementation or more railtypes

(svn r2389) - Feature: [newgrf] Implement the mechanism for handling newgrf callbacks.
- Feature: [newgrf] Implement the 'refit capacity' callback.

(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 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 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 r1290) Added type to typedef struct Engine and filled in the same data as in type in vehicle
it was kind of lame that you should use AircraftVehInfo(), ShipVehInfo() etc. if you wanted to know what type the engine is

(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.