Merge remote-tracking branch 'cigaes/master'

* cigaes/master:
  lavfi/vf_yadif: use standard options parsing.
  lavfi/vf_unsharp: use standard options parsing.
  lavfi/vf_transpose: use standard options parsing.
  lavfi/vf_pad: use standard options parsing.
  lavfi/vf_fps: use standard options parsing.
  lavfi/vf_fade: use standard options parsing.
  lavi/vf_drawbox: use standard options parsing.
  lavfi/vf_delogo: use standard options parsing.
  lavfi/vf_decimate: use standard options parsing.
  lavfi/vf_crop: use standard options parsing.
  lavfi/af_volume: use standard options parsing.
  lavfi/vf_tile: use standard options parsing.
  lavfi/avf_concat: use standard options parsing.
  lavfi: add common code to handle options parsing.
  lavf/vobsub: free index pseudo-packet.
  ffmpeg: fix freeing of sub2video frame.
  lavfi: add sine audio source.
  lavu/opt: add AV_OPT_TYPE_DURATION.
  lavfi/concat: fix silence duration computation.
  lavf/concatdec: support seeking.

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