add GL dependency and context initialisation
remove TODO comment as it's implemented
create and destroy framebuffer object
initial gl scaling, still buggy
convert vdp blend_state to gl blend func and eq
use gl scaling in softVdpOutputSurfaceRenderOutputSurface
create gl texture in softVdpOutputSurfaceCreate and delete in {}destroy.
store height and width too
copy data from cairo surface to texture in softVdpVideoMixerRender
use already filled textures in softVdpOutputSurfaceRenderOutputSurface
actually reserve texture in softVdpOutputSurfaceCreate
use glTexSubImage2D instead of glTexImage2D
move texture parameter setting to its creation place
render directly into texture in softVdpOutputSurfaceRenderOutputSurface
use gl blending in softVdpOutputSurfaceRenderBitmapSurface
remove commented code
drop vdpau-va.c and vdpau-va.h
remove references to vdpau-va
ensure FBO bound
draw from texture in softVdpPresentationQueueDisplay