Fix the caps of flacenc, the reference encoder only support 24 bits in
32 bits.
Set streamheader on output caps.

Fixes https://bugzilla.gnome.org/show_bug.cgi?id=671911

subclass from videosink.
Propose videometa upstream because we can handle it with the video api.

https://bugzilla.gnome.org/show_bug.cgi?id=671534

Reuse cleanup methods to make sure we remove all pads correctly

Release the lock before setting the caps on the srcpad, which triggers an event,
which could eventually call back into us and cause a deadlock.

Set the caps after we activated the pad or else it will just fail.

Use GstAudioInfo to generate output caps.

https://bugzilla.gnome.org/show_bug.cgi?id=671534

udpsrc/udpsink are almost always used with RTP, so let's use an
RTP port as the default port.  It's unclear why 4951 was used, it
goes back to early commits in CVS.

Fix the output rowstride, we need to take the stride of the output video frame.
Since we are also dealing with planes, take the plane data and stride.
Don't store the same info twice in different variables.

Conflicts:
	ext/wavpack/gstwavpackparse.c
	sys/v4l2/gstv4l2bufferpool.c
	sys/v4l2/gstv4l2bufferpool.h
	sys/v4l2/gstv4l2videooverlay.c

https://bugzilla.gnome.org/show_bug.cgi?id=671299



Signed-off-by: Oleksij Rempel (Alexey Fisher) <bug-track@fisher-privat.net>

... which also happens to make some more unit tests pass.

... at least sufficiently to aid in recognizing rewritten header buffer
making unit test pass.