Merge remote-tracking branch 'qatar/master'

Merge remote-tracking branch 'qatar/master'

* qatar/master:
  WavPack demuxer: do not rely on index when timestamp is not in indexed range.
  WavPack demuxer: store position of the first block in index.
  WavPack decoder: implement flush function
  avconv: Separate initialization from the main transcode loop.

Conflicts:
	avconv.c

Merged-by: Michael Niedermayer <michaelni@gmx.at>