qtmux: use timestamp delta as duration if possible

https://bugzilla.gnome.org/show_bug.cgi?id=696437
theorapay: add delta-unit to output frames
matroskademux: handle TrueHD audio codec id

https://bugzilla.gnome.org/show_bug.cgi?id=697113
v4l2: fix printf format compiler warning in debug message
matroskademux: fix some debug messages
rtpssrcdemux: Don't cross the internal links

We had the wrong condition to check for the internal links, so RTP and RTCP
pads got crossed!
rtpssrcdemux: Simplify event forwarding

Use the gst_pad_forward() mechanic, this way we won't miss pads that are
added while we are pushing
rtpssrcdemux: Remove unused GstSegment
rtpssrcdemux: No need to explicitely forward the caps

They are forwarded with the other events
rtpssrcdemux: Only forward stick events while holding the sinkpad stream lock

Otherwise we get a race where if the RTCP packet comes in first and while
it is added the pads, the segment event arrives on the RTP stream, the event
may be lost completely and never forwarded.
v4l2: improve debug
v4l2: free all queued buffers

Don't just loop over the first num_queued buffers but loop over
all the buffers and check if they need to be freed. It is possible that
not all buffers are queued and then the entry in our array will be NULL.
Those buffers that are not queued were freed in stop().

Fixes https://bugzilla.gnome.org/show_bug.cgi?id=696651
rtspsrc: Proxy the multicast-iface property of udpsrc
spectrum: remove old since comment
flacenc: remove old since comments and update logging

Don't pretend that we have a timestamp on a buffer when we never set one.
level: subdivide buffers for sample accurate interval handling

Previously we would skip level message when processing buffers > the requested
interval. Also the message frequency would contain quite some jitter due to only
considering them at the end of buffers.

Cleanup the tests while we're at it.
rtpsbcdepay: Rank as secondary

This way, it will be selected by decodebin
Bug reported by andreas.fenkart@streamunlimited.com

https://bugzilla.gnome.org/show_bug.cgi?id=697227
vp8dec: Improve logging when vpx_codec_peek_stream_info fails

Decode failures and missing keyframes should get different debug
output.

https://bugzilla.gnome.org/show_bug.cgi?id=697232
level: resync on discont

Drop pending data on discont and start a new cycle with a new base timestamp.
Cleanup some variables.
osxvideo: include pthread.h to fix compiler warning

https://bugzilla.gnome.org/show_bug.cgi?id=697303