lavfi: switch to AVFrame.

Deprecate AVFilterBuffer/AVFilterBufferRef and everything related to it
and use AVFrame instead.
mpegvideo_enc: drop support for reusing the input motion vectors.

This misfeature is most likely completely useless and conflicts with
removing the mpegvideo-specific fields from AVFrame. In the improbable
case it is actually useful, it should be reimplemented in a better way.
Revert "build: disable iconv by default."

This reverts commit 9ad3cd5b5f848eb3cd033be515d34296f099148b.

The misdetection on OS X should be fixed, we will only get
problem reports if auto-detection is enabled.
Merge commit '7e350379f87e7f74420b4813170fe808e2313911'

* commit '7e350379f87e7f74420b4813170fe808e2313911':
  lavfi: switch to AVFrame.

Conflicts:
	doc/filters.texi
	libavfilter/af_ashowinfo.c
	libavfilter/audio.c
	libavfilter/avfilter.c
	libavfilter/avfilter.h
	libavfilter/buffersink.c
	libavfilter/buffersrc.c
	libavfilter/buffersrc.h
	libavfilter/f_select.c
	libavfilter/f_setpts.c
	libavfilter/fifo.c
	libavfilter/split.c
	libavfilter/src_movie.c
	libavfilter/version.h
	libavfilter/vf_aspect.c
	libavfilter/vf_bbox.c
	libavfilter/vf_blackframe.c
	libavfilter/vf_delogo.c
	libavfilter/vf_drawbox.c
	libavfilter/vf_drawtext.c
	libavfilter/vf_fade.c
	libavfilter/vf_fieldorder.c
	libavfilter/vf_fps.c
	libavfilter/vf_frei0r.c
	libavfilter/vf_gradfun.c
	libavfilter/vf_hqdn3d.c
	libavfilter/vf_lut.c
	libavfilter/vf_overlay.c
	libavfilter/vf_pad.c
	libavfilter/vf_scale.c
	libavfilter/vf_showinfo.c
	libavfilter/vf_transpose.c
	libavfilter/vf_vflip.c
	libavfilter/vf_yadif.c
	libavfilter/video.c
	libavfilter/vsrc_testsrc.c
	libavfilter/yadif.h

Following are notes about the merge authorship and various technical details.

Michael Niedermayer:
  * Main merge operation, notably avfilter.c and video.c
  * Switch to AVFrame:
    - afade
    - anullsrc
    - apad
    - aresample
    - blackframe
    - deshake
    - idet
    - il
    - mandelbrot
    - mptestsrc
    - noise
    - setfield
    - smartblur
    - tinterlace
  * various merge changes and fixes in:
    - ashowinfo
    - blackdetect
    - field
    - fps
    - select
    - testsrc
    - yadif

Nicolas George:
  * Switch to AVFrame:
    - make rawdec work with refcounted frames. Adapted from commit
      759001c534287a96dc96d1e274665feb7059145d by Anton Khirnov.
      Also, fix the use of || instead of | in a flags check.
    - make buffer sink and src, audio and video work all together

Clément Bœsch:
  * Switch to AVFrame:
    - aevalsrc
    - alphaextract
    - blend
    - cellauto
    - colormatrix
    - concat
    - earwax
    - ebur128
    - edgedetect
    - geq
    - histeq
    - histogram
    - hue
    - kerndeint
    - life
    - movie
    - mp (with the help of Michael)
    - overlay
    - pad
    - pan
    - pp
    - pp
    - removelogo
    - sendcmd
    - showspectrum
    - showwaves
    - silencedetect
    - stereo3d
    - subtitles
    - super2xsai
    - swapuv
    - thumbnail
    - tile

Hendrik Leppkes:
  * Switch to AVFrame:
    - aconvert
    - amerge
    - asetnsamples
    - atempo
    - biquads

Matthieu Bouron:
  * Switch to AVFrame
    - alphamerge
    - decimate
    - volumedetect

Stefano Sabatini:
  * Switch to AVFrame:
    - astreamsync
    - flite
    - framestep

Signed-off-by: Michael Niedermayer <michaelni@gmx.at>
Signed-off-by: Nicolas George <nicolas.george@normalesup.org>
Signed-off-by: Clément Bœsch <ubitux@gmail.com>
Signed-off-by: Hendrik Leppkes <h.leppkes@gmail.com>
Signed-off-by: Matthieu Bouron <matthieu.bouron@gmail.com>
Signed-off-by: Stefano Sabatini <stefasab@gmail.com>

Merged-by: Michael Niedermayer <michaelni@gmx.at>
rawdec: work with refcounted frames.

Adapted from commit 759001c534287a96dc96d1e274665feb7059145d
by Anton Khirnov.

Also, fix the use of || instead of | in a flags check.
lavc/rawdec: set field order on decoded frame.
ffmpeg: do not give away our reference to the frame.

Note: the logic here is temporary until the updates to
ffmpeg.c are merged.
fate: disable sub2video

Signed-off-by: Michael Niedermayer <michaelni@gmx.at>
doc: fix examples.
lavu/frame: fix not/note typo in doxy.
Merge commit '6e7b50b4270116ded8b874d76cb7c5b1a0341827'

* commit '6e7b50b4270116ded8b874d76cb7c5b1a0341827':
  mpegvideo_enc: drop support for reusing the input motion vectors.

Conflicts:
	libavcodec/motion_est.c

Merged-by: Michael Niedermayer <michaelni@gmx.at>
lavfi/hue: add an optimized direct path.
lavfi/hue: reindent.
Merge remote-tracking branch 'cehoyos/master'

* cehoyos/master:
  Revert "build: disable iconv by default."

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