vdpau: reactivate long decoding time debug message
vdpau: keep video surfaces for another cycle
vdpau: create only a single vdpau device
vdpau: make sure buffers a full before returning a picture
vdpau: move common attributes into vdpau context
vdpau: drop pixmap magic, it violates the spec
vdpau: reduce number of render pics
vdpau: cosmetics