Automatic update of common submodule

From a72faea to a942293
tests: use GST_*_1_0 environment variables everywhere

The _1_0 suffixed environment variables override the
non-suffixed ones, so if we're in an environment that
sets the _1_0 suffixed ones, such as jhbuild, we need
to set those to make sure ours actually always get
used.
Disable libswscale/avvideoscale plugin until it works at least somewhat

It needs some fixing.
libav: fix checks for internal libav configure options

https://bugzilla.gnome.org/show_bug.cgi?id=691723
avdec_aac: disable for autoplugging until it gets fixed

Currently outputs garbled audio. Use faad in the meantime.

https://bugzilla.gnome.org/show_bug.cgi?id=690940
avenc_aac: downgrade to RANK_NONE until it gets fixed

Currently just fails to initialize.

https://bugzilla.gnome.org/show_bug.cgi?id=691617
avauddec: fix garbled audio decoding in some cases

Calculate output buffer size based on the number of
samples, channels and bytes per sample. The buffer
size was calculated based on linesize, which may
be larger than what's required.

https://bugzilla.gnome.org/show_bug.cgi?id=690940
avauddec: fix decoding of mono audio as well

https://bugzilla.gnome.org/show_bug.cgi?id=690940
Revert "avdec_aac: disable for autoplugging until it gets fixed"

This reverts commit c5980dc52ac57cf0147ed269e3b2c863d7251f84.

It's fixed now.

https://bugzilla.gnome.org/show_bug.cgi?id=690940
Automatic update of common submodule

From a942293 to 2de221c
Fuck libav. Long live ffmpeg!