(svn r5723) - Move the declaration of DrawRoadDepotSprite() out of functions.h (but I'm not too happy with the new header)
- Use DiagDirection instead of plain int for the orientation of the depot graphics
- Rename the associated data tables with sprites to something more meaningful

(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 r223) -Fix: Const correctness and miscellaneous fixes. Thank you Tron for your diligent fixing of warnings (and some possibly bugs) (Tron)
-CodeLayout: Remove trailing spaces and Windows linebreaks