Set face/wall/floor flags from Build sprites
Add CVar for drawing weapons in the althud
Fixed build on compilers other than MSVC

No more "Call to 'LittleShort' is ambiguous" error
Merge branch 'fix_build_nonmsvc' of https://github.com/alexey-lysiuk/gzdoom
- added menu entry for newly added hud_showweapons CVAR.
Q&D port of decal code to draw generic wall sprites

- This still doesn't use all the sprite properties correctly. It also
  looks like they're going to need different code to build the clipping
  arrays. But at least wall sprites are drawn at the proper angle now!
Merge branch 'master' of github.com:rheit/zdoom