This implements the 0x10 frame format for Interplay MVE movies. The
format is a variation on the 0x06 format with some changes. In addition
to the decoding map there's also a skip map. This skip map is used to
determine what 8x8 blocks can change in a particular frame.

This format expects to be able to copy an 8x8 block from before the last
time it was changed. This can be an arbitrary time in the past. In order
to implement this this decoder allocates two additional AVFrames where
actual decoding happens. At the end of a frame decoding changed blocks
are copied to a finished frame based on the skip map.

The skip map's encoding is a little convulted, I'll refer to the code
for details.

Values in the decoding map are the same as in format 0x06.

Signed-off-by: Hein-Pieter van Braam <hp@tmm.cx>