* qatar/master:
  rv34: Handle only complete frames in frame-mt.
  MPV: set reference frame pointers to NULL when allocation of dummy pictures fails
  configure: die if x11grab dependencies are unavailable
  zerocodec: factorize loop
  avconv: fix the resampling safety factors for output audio buffer allocation
  avconv: move audio output buffer allocation to a separate function
  avconv: make the async buffer global and free it in exit_program()

Conflicts:
	ffmpeg.c
	libavcodec/mpegvideo.c
	libavcodec/rv34.c
	libavcodec/zerocodec.c
Merged-by: Michael Niedermayer <michaelni@gmx.at>