Log Message:
update to 0.10.15
changes:
-amrnbenc: give element a rank (SECONDARY) so it's autoplugged
-rmdemux: descramble sipro audio before pushing out
-x264enc: fix up codec_data / avcC header construction some more
-x264enc: Put pixel-aspect-ratio from input into the src pad caps

pkgsrc note: patch-ab was added to work around an API incompatibility
to pkgsrc's old libx264, can be removed if libx264 gets updated (which
is currently not possible due to pkgsrc's even older ffmpeg)
I've tested gst-x264enc only with a simple testcase (videotestsrc!x264enc)
and it seems to work so far.