h264parse: Use slice type to determine if frame is keyframe

This is the same behaviour as pre-baseparse-refactoring

https://bugzilla.gnome.org/show_bug.cgi?id=705598
tests: fix build of baseaudiovisualizer test with subdir-objects option

https://bugzilla.gnome.org/show_bug.cgi?id=705350
tests: create/remove orc directory at proper time

Before automake creates .deps directories, and during distclean.

https://bugzilla.gnome.org/show_bug.cgi?id=705350
build: add subdir-objects to AM_INIT_AUTOMAKE

Fixes warnings with automake 1.14.

https://bugzilla.gnome.org/show_bug.cgi?id=705350
aiffparse: fix buffers initialisation

https://bugzilla.gnome.org/show_bug.cgi?id=705674
aiffparse: send start stream event

https://bugzilla.gnome.org/show_bug.cgi?id=705674
aiffparse: set missing layout field in srcpad caps

https://bugzilla.gnome.org/show_bug.cgi?id=705674
aiffparse: don't unref NULL buffer
aiffparse: fix CAPS query

Was causing criticals in decodebin/playbin because the caps
query done when exposing pads would return ANY caps.
tests: mpeg2enc: fix 'Got data flow before stream-start event' failure
tests: mplex: fix 'Got data flow before stream-start event' failure
uvch264mjpgdemux: fix event ordering
tests: uvch264demux: send stream-start events and fix event order
mpegdemux: send codec tag for each stream
hlsdemux: add support for redirections
aiffparse: fix SSND data size

AIFF chunk size does not include the chunk header size (8 bytes), so the
SSND data size is equal to the chunk size minus the SSND header size (8
bytes).

https://bugzilla.gnome.org/show_bug.cgi?id=705675
vc1parse: Fix seq hdr STRUCT_A handling for advanced profile.

The Sequence Header Data Structure STRUCT_A for advanced profile
may be eight consecutive zero bytes.Don't try to override the
width and height values in this case.

https://bugzilla.gnome.org/show_bug.cgi?id=705667
vc1parse: Fix the SequenceLayer handling for advanced profile.

The Sequence Header Data Structure STRUCT_C for Advanced Profile
has only a one valid field which is the profile indicator. Don't
use the reserved fields for fps update like Simple/Main profile.

https://bugzilla.gnome.org/show_bug.cgi?id=705667
srtpdec: Don't error on invalid packet, just drop it
srtpdec: Refactor code a bit

Simplify the error handling case and get the packet push out of the if()