po: Update translations
matroskademux: Don't skip all video frames until the first keyframe

Instead do it like all other demuxers and let parsers and decoders
handle that. The keyframe information inside the container might
be completely wrong like in the sample file of the bug report,
and if it is correct and we push no keyframes, then the parsers
and decoders will handle that properly anyway.

https://bugzilla.gnome.org/show_bug.cgi?id=682276
rtpvp8pay: Don't leak input buffers

https://bugzilla.gnome.org/show_bug.cgi?id=722414
v4l2: guard use of ENODATA with #ifdef

Not all systems with v4l have ENODATA defined, so check that we have it
before attempting to use it.

https://bugzilla.gnome.org/show_bug.cgi?id=722953
wavparse: Ignore Broadcast Wave Format (BWF) tags when searching for 'fmt' chunk

https://bugzilla.gnome.org/show_bug.cgi?id=723125
effectv: fix doc section of revtv element