Upload block transfers to FBOs when from ram.
Don't try to seek the video with too few packets.

Conservatively we seem to need approximately 6, which any video ought to
be longer than.
Forget video end when more packets are added.

Good for looping videos, for example Burnout.
Typo.
Merge pull request #4828 from unknownbrackets/mpeg-minor

Fix some issues with looping videos, and videos added in tiny chunks