(svn r4384) -Codechange: rail drawing code
-Added a function to obtain the axis of a waypoint
-Moved the waypoint layout tables from the depot layout tables into an own one
-Use GetRailTileSubtype

(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 r2702) -Codechange: Cleaned up the sprite code and replaced many magic numbers
by enums. There remains work in gfx.c to move the "transparency" and
"recolor" bits around to make space for more sprites. However, 2800
additional sprites can now be loaded. There also remains cleanup and
Doxygen work on many of the header files.

(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)