This uses the automatic YCoCg conversion inside Schroedinger to
encode/decode RGB. Only works in intra-only mode, similar to 10-
and 16-bit, since RGB is technically a >8-bit format for Dirac
purposes. This depends on schroedinger-1.0.12, which is unreleased.
Also move schroedinger plugin. This creates a new library,
gstbasevideo-0.10, which will probably be merged back into
gstvideo-0.10 when this is moved back to -base.
