- Added query feature related to DXT compressed textures.
- Added compressed textures support for D3D9.
- Fixed minor bugs in OpenGL related to compressed textures handling.
- Properly handle compressed textures in D3D8 and Software drivers (Those drivers doesn't support compressed textures).

git-svn-id: svn://svn.code.sf.net/p/irrlicht/code/trunk@4450 dfc29bdd-3216-0410-991c-e03cc46cb475