*p_es->p_demux_data is available in p_config->p_demux_data so that the input
can pass information directly to the decoder.

*First application: aspect ratio for DVD is read from the ifo (should fix
the buf with aspect ratio in anamorphic DVDs).

*The DVD plugin also copy the spu yuv palette in p_demux_data so that the
spudec can display subtitle with the right color (sam !).

*Removed duplicate code and useless lock in gtk.