decoder: cosmetics
decoder: merge DecoderError into DecoderProcess
decoder: Simplify DecoderWaitUnblock() proto
contrib: don't build glib by default

We only need it as a dependency of another library (fluidsynth)
playlist demux: do not use index()

marked as LEGACY in POSIX.1-2001.
POSIX.1-2008 removes the  specifications  of  index()
and rindex(), recommending strchr(3) and strrchr(3) instead.
dvbpsi: do not print a message if message type is DVBPSI_MSG_NONE

This value is documented as '/*!< No messages */'
dvbpsi: do not spam the debug log at each PMT update

dvbpsi own debug messages are not needed to debug VLC modules
demux: asf: wait keyframe on index seek too

Index could be post keyframe type !
demux: asf: reset PCR on seek
demux: asf: correctly flag invalid time
Merge remote-tracking branch: upstream/master