[omxplayer] Don't sync up to passthrough audio packets - let GPU handle it

This code was just broken.
When sync is lost it attempts to identify how many bytes to skip to regain sync,
but does nothing with that skip count - just drops the whole frame.

It also stops EAC3 from being passed through.

The GPU has similar sync detection code which does avoid dropping the whole frame,
so just pass the packets through and let GPU deal with it.
[dvdplayer] exerimental: don't raise priority of audio thread
[mmalcodec] Introduce a preroll period to buffer up frames on startup
[omxplayer] Add ability to log more timestamp info in extra debug settings
[omxplayer] Add ability to dump out audio/video data for later debugging
[audio] Add settings option to boost centre channel when downmixing

This allows a dB volume increase to be added to centre channel.
This can help improve dialgue in the presence of background music/effects.
It can go up to 30dB for testing purposes, but value of 6 is probably more reasonable.
It is recommended to ensure "Normalise levels on downmix" is enabled when boosting by large values to avoid clipping.

Should work with Pi Sink (dvdplayer/paplayer) and omxplayer
[omxcore] Skip out of flush on error
[SinkPi] Handle multichannel layout more like OMXAudio
[PiSink] Allow audio output latency to be set in settings
rbp: Use new dispmanx function for vsync callbacks
Revert "rbp: Use new dispmanx function for vsync callbacks"

This reverts commit afbf8fbceaa6649fb4a6bbd9a1cee6087590412b.
[rbp] Default extract thumbnails to false

It can take 80 seconds for a single file on a Pi. It can cause crashes with out-of-memory errors.
It genereates a lot of support issues. Best to default to disabled and let users enable it if they must
[cec] Add settings for configuring button repeats
Revert "[omxplayer] Add ability to dump out audio/video data for later debugging"

This reverts commit 417416bd29d00f1b42c77488d06e9e6840b8c4f4.
[omxplayer] Add ability to dump out audio/video data for later debugging
[cec] Don't discard buttons when repeat mode is enabled
[cec] Temp - more logging
[resamplepi] Try to report the same numbers as ffmpeg
[dvdplayer] New scheme for PLL adjustment for video clock
MMAL: Use Component Logging