Silicon Graphics RLE 8-bit video decoder

Signed-off-by: Vittorio Giovara <vittorio.giovara@gmail.com>
Silicon Graphics Motion Video Compressor 1 & 2 decoder

Signed-off-by: Vittorio Giovara <vittorio.giovara@gmail.com>
Silicon Graphics Movie demuxer

Signed-off-by: Vittorio Giovara <vittorio.giovara@gmail.com>
fate: add tests for SGI RLE and MVC1&2 decoders