the interface but it is more correct way (Microsoft even have a
  resource type of volume).
- Moved usage, format, allocatedMemory and size onto the resource
  class structure.
- Refactored Preload for classes that inherit BaseTexture, preload now
  binds the texture instead of bind texture calling preload, bindTexture
  allocated a glTexture if there isn't one.
- Added two new class static members BaseTexture_CleanUp and
  Resource_CleanUp that should be called by classes that implement
  BaseTexture or Resource.