add .gitignore
support for visual studio express
doom classic fixes and stub support for mac os x
timidity mac os x / xcode project
idLib fixes and some support for mac os x
game-d3xp support for mac os x
Had problems with the reinterpret_cast on apiObject with Xcode4/clang/llvm compiler.
Made use of GLuint for apiObject instead of void pointer (the current version of this source tree is OpenGL dependent).
Check for buffer generation with BUFFER_NOT_GENERATED.
Allow multi-platform compilation in IsWriteCombined() (not implemented outside of Windows).
Doom3BFG fixes and null stubs to prepare support for mac os x
additional fixes preparing for mac os x support
null sound system stub missed in a previous commit
Xcode 4.6.2 workspace & projects, should build on Mac OS X

- does not initialize due to lack of an OpenGL 3.2 compatibility
profile on Mac OS X
- various codebase changes to support non-Windows platforms
- NULL stubs for sound engine, achievements, localuser, savegame,
session_local & signin
- support for Visual Studio Express