Use avcodec_encode_audio2() with libavcodec v54 (SF-175).
Fix compile warning about planar_to_interleaved() unused.

And make it more clear which conversion function is needed for which
version of libavcodec.
Fix setting muxer-specific options (SF-197).

Patch provided by Peter Egro <pegro@users.sf.net>
Add changing priority of decklink callback thread.
Document new priority property of decklink producer.
Fix sample count and rate with audio_index=all.
use rational fps value to calc frames count
Let DOUBLE_MLT_POSITION be defined in CFLAGS.
Fix aspect ratio in resize filter with multi consumer.
Add HTML escaping to metadata publishing script.
Move the aspect ratio for multi consumer from mlt_frame.
Add support for Qt 5, drop support for Qt 3 and KDE 3.
Add faststart muxing flag to MP4 presets.
Cleanup x264 stats files when "passlogfile" supplied.
Fix qglsl consumer for Qt 5.
Add "close glsl" event to glsl.manager service.

Qt 5 apps (and possibly others) must use this because the OpenGL context
for rendering needs to be created and destroyed on the thread on which
it is actually used. This should be fired on the glsl.manager filter
instance inside of a consumer-thread-stopped mlt_event listener.
Fix qglsl on Qt 5 for OS X.
Fix building qimage module on Qt 5 on Windows.
fix division on 255 (v2)