MAIN: Enable the debug manager before the other subsystems
BUILD: Add dependency on OGRE (>= 1.9)
BUILD: Add stubs for compiling Objective C++ on Mac OS X
GRAPHICS: Stub Mac OS X graphics utility functions
COMMON: Rename FORCEINLINE to XOREOS_FORCEINLINE

OGRE also defines a FORCEINLINE
BUILD: Remove the warning against non-virtual destructors

Unfortunately, OGRE is a heavy offender...
COMMON: Add debug channel for Ogre
GRAPHICS: Start adding Ogre support

This just stuffs Ogre into an SDL2 window, so that
SDL2 and Ogre can be used together. Nothing else
is yet functioning.
ALL: Remove everything related to the old graphics stack

All functionality will be re-added in turn with Ogre bindings.
BUILD: Restructure the Makefile.am a bit

Adding new files should be less annoying now, and diffs
should read clearer (and hopefully merge better), since we
now don't have to add a \ to the end of the previous line.
Graphics: Add a new TextureManager for Ogre
Graphics: Add a new CursorManager for Ogre
ENGINES: Hook up the new CursorManager
GRAPHICS: Convert our old PixelFormat to Ogre's
GLEW: Remove GLEW

We don't need it anymore; we use Ogre for OpenGL stuff.
GRAPHICS: Reintroduce dumpTGA for textures
GRAPHICS: Add TextureManager::getInvisible()
Graphics: Add a MaterialManager for Ogre
GRAPHICS: Add an Ogre frame listener to advance animations
COMMON: Add functions to generate unique number IDs