(svn r2868) Change the way NewGRFs are loaded: The loading process i no longer bolted onto the normal graphics loading.
This has two major advantages:
- Removal of a maze of global variables and distinction of cases from the sprite loading routines, which weren't directly related to the loading process in the first place
- NewGRF actions no longer occupy sprite slots - for example when using DBSetXL this saves about 2000 slots! (you could regard this as a bug fix)
If i didn't make a major mistake this change should have no negative effect on NewGRF support, please test!

(svn r2866) Move all functions and tables which aren't directly involved in managing the sprite heap to a new file gfxinit.c.
This doesn't ease the global variable mess, but makes the distinction between sprite heap and gfx loading routines easier.

(svn r2862) Return a proper version number, when testing the TTDPatch version in the SkipIf action. Pretend to be version 2.0.1 alpha 49 for now.
Also change the type of the variables, which get compared, to uint32, because the values are at most 32bits wide and always seem to be unsigned.

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

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

(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 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