gsdx ogl:
* preliminary work for GL4.4 extensions (ARB_clear_texture & ARB_multi_bind). Disabled until I got a 4.4 driver
Note: I plan also to use ARB_buffer_storage
* compute texture gl option in the constructor (avoid a couple of swith case)
* redo texture unit management. Unit 0-2 for shaders, Unit 3 for texture operations. MultiBind will allow to bind 
shader input without disturbing texture binding points.


git-svn-id: http://pcsx2.googlecode.com/svn/trunk@5711 96395faa-99c1-11dd-bbfe-3dabce05a288