Initial test to VR'ify the loading screens
Default supersample to off to stop potential black screen at startup!
Allow setting of experimental orientation quaternion support via GUI
Check for framebuffer creation success. If failed, turn off supersampling (the most likely cause - framebuffer too big)
Merge branch 'quaternions_on_gui'
Merge branch 'fix_remaining_non_vr_gui'
Ensure load screen VR GUI responds to head tracking. Hacky - blank GUI at last transition until valid world.