pesparse: Refactory secondary PES extension handling

Some streams had wrong values for the stream_id_extension, make sure
we only remember the valid ones.

For streams with PES_extension_field_length == 0, assume there's nothing
else.

For streams that state they have a TREF extension but don't have enough
data to store it, just assume it was produced by a non-compliant muxer
and skip the remaining data.

Only store remaining data in stream_id_extension_data instead of storing
data we already parse.
.gitignore: Update for new files to ignore
dvbbasebin: fix criticals when trying to cast a GstPad to a GstElement

message->src might be a GstPad. Observed during gst-inspect-1.0 -a
interaudiosrc: make silence memory actually contain silence

instead of random data. Reported by Marco Micheletti on
gstreamer-devel.
examples: remove prehistoric examples
ext: Use new flush vfunc of video codec base classes and remove reset implementations
examples: remove another obsolete example
dashdemux: remove incorrect timestamp scaling.

When using a SegmentTemplate element, the timestamps of the buffers
output by dashdemux are incorrect, causing problems downstream.

The reason is that GstMediaSegment start times are calculated (in
gst_mpdparser_get_chunk_by_index) by multiplying segment index by
segment duration and then scaling the result according the `timebase'
attribute from the MPD. However, the segment duration is already a
GstClockTime (i.e., it has already been scaled according to the timebase
from the MPD and converted to a nanosecond value), so multiplying it by
the segment index will give the correct timestamp without the need for
any further scaling.

https://bugzilla.gnome.org/show_bug.cgi?id=705679
dashdemux: offset segment numbers by startNumber

For SegmentTemplate elements containing a startNumber attribute, the
`number' member of GstMediaSegments should be offset by the value of
startNumber; however, this is not currently the case. As a result, the
first URI(s) requested by the download loop will be wrong.

This commit ensures that segment numbers will be offset by startNumber
when one is present in a SegmentTemplate element.

https://bugzilla.gnome.org/show_bug.cgi?id=705661
srtpdec: fix buffers being dropped due to shadowed variable

Spotted by gstblub@gmail.com.

https://bugzilla.gnome.org/show_bug.cgi?id=706091
mpeg4videoparse: Reparse the config if the size changed

Also only re-issue the caps update if the part of the config that
changed is one we care about.
aiffparse: fix push mode

Fix push mode by handling sink events (CAPS, SEGMENT) properly.

https://bugzilla.gnome.org/show_bug.cgi?id=705993
aiffparse: s/newsegment/segment/

https://bugzilla.gnome.org/show_bug.cgi?id=705993
aiffparse: don't leak adapter
aiffparse: add tests

https://bugzilla.gnome.org/show_bug.cgi?id=705993
tests: fix state change order in aiffparse test

Do state changes from sink to src. Fixes race condition in
pull mode test where the source will start up and push buffers
to queue/identity or aiffparse before the main thread has
managed to set them to playing yet.
tests: fix some leaks in aiffparse unit test
aiffparse: fix copyright
test: fix compiler warning in aiffparse test on 32-bit x86
jpegparse: Forward segment event after caps

Store it until we know what our caps are.