Additional "baked" code.

Continued adding handling of a fully baked more to the Bezier code. This
will have to be rippled into the feather code (to account for the number
of key frames).

Opacity seems to work apparently taking advantage of yet another special
case in Nuke. If linear interpolation is used (as it always is in baked
mode), then a sequence of {frame value} is all that's needed.