Merge and adapt commit d28cb849 by Anton Khirnov.

Found-by: durandal_1707
Signed-off-by: Michael Niedermayer <michaelni@gmx.at>

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

Also fixes #2455.
Signed-off-by: Paul B Mahol <onemda@gmail.com>

Signed-off-by: Paul B Mahol <onemda@gmail.com>

* qatar/master:
  dsputil: Make dsputil selectable

Conflicts:
	configure
	libavcodec/Makefile
	libavcodec/x86/Makefile
	libavcodec/x86/constants.c
	libavcodec/x86/dsputil_mmx.c
	libavcodec/x86/dsputil_mmx.h
Merged-by: Michael Niedermayer <michaelni@gmx.at>

* commit '85deb51a':
  h264: Only initialize dsputil if error resilience is enabled

Conflicts:
	libavcodec/h264.c
Merged-by: Michael Niedermayer <michaelni@gmx.at>

* ubitux/shorthand-cleanup:
  lavfi/setfield: switch to an AVOptions-based system.
  lavfi/asettb: switch to an AVOptions-based system.
  lavfi/aselect: switch to an AVOptions-based system.
  lavfi/sine: switch to an AVOptions-based system.
  lavfi/deshake: switch to an AVOptions-based system.
  lavfi/tinterlace: switch to an AVOptions-based system.
  lavfi/tile: switch to an AVOptions-based system.
  lavfi/concat: switch to an AVOptions-based system.
Merged-by: Michael Niedermayer <michaelni@gmx.at>

* commit '62844c3f':
  h264: Integrate clear_blocks calls with IDCT

Conflicts:
	libavcodec/arm/h264idct_neon.S
	libavcodec/h264idct_template.c
	libavcodec/x86/h264_idct.asm
Merged-by: Michael Niedermayer <michaelni@gmx.at>

* commit 'e8cafd27':
  h264: Clear the mb members via memset instead of using dsputil

Conflicts:
	libavcodec/h264.c
Merged-by: Michael Niedermayer <michaelni@gmx.at>

* commit '6d25c9db':
  dsputil: Make square put/avg_pixels functions local to h264qpel

Conflicts:
	libavcodec/dsputil.c
Merged-by: Michael Niedermayer <michaelni@gmx.at>

* commit '2e81acc6':
  x86inc: Fix number of operands for cmp* instructions
  af_channelmap: fix uninitialized variable use introduced in ba8efac9
  lavfi: add a bump and docs entries for the AVOptions switch

Conflicts:
	Changelog
	doc/APIchanges
	libavfilter/version.h
Merged-by: Michael Niedermayer <michaelni@gmx.at>

* ubitux/lavfi-mixed-short-long:
  lavfi: restore mixed short/long option support with the new system.
Merged-by: Michael Niedermayer <michaelni@gmx.at>

* commit '8114c101':
  lavfi: add avfilter_get_class().

Conflicts:
	libavfilter/avfilter.h
Merged-by: Michael Niedermayer <michaelni@gmx.at>

process_unnamed_options() is renamed to process_options() and its code
is heavily based on av_opt_set_from_string().

* commit '4d1f31ea':
  lavfi: make AVFilterContext export filter options.

Conflicts:
	libavfilter/avfilter.c
Merged-by: Michael Niedermayer <michaelni@gmx.at>

* commit '62549f96':
  lavfi: error out when options are provided to a filter that does not take any

Conflicts:
	libavfilter/avfilter.c
Merged-by: Michael Niedermayer <michaelni@gmx.at>

* commit 'c43a7eca':
  lavfi: remove now unused args parameter from AVFilter.init

Conflicts:
	libavfilter/avfilter.c
	libavfilter/buffersrc.c
	libavfilter/f_select.c
	libavfilter/src_movie.c
	libavfilter/vf_alphamerge.c
	libavfilter/vf_drawtext.c
	libavfilter/vf_lut.c

Not merged (yet) because there are still many filters that use the args
parameter.
Merged-by: Michael Niedermayer <michaelni@gmx.at>

* commit '7b3eb745':
  vsrc_testsrc: switch to an AVOptions-based system.

Conflicts:
	doc/filters.texi
	libavfilter/vsrc_testsrc.c
Merged-by: Michael Niedermayer <michaelni@gmx.at>

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

* commit 'a42d6e6c':
  vsrc_movie: switch to an AVOptions-based system.

Conflicts:
	doc/filters.texi
	libavfilter/src_movie.c
Merged-by: Michael Niedermayer <michaelni@gmx.at>

* commit 'b7b3302f':
  vsrc_nullsrc: switch to an AVOptions-based system.

Conflicts:
	libavfilter/vsrc_nullsrc.c
Merged-by: Michael Niedermayer <michaelni@gmx.at>

* commit '7bc1a883':
  vsrc_color: switch to an AVOptions-based system.

Conflicts:
	doc/filters.texi
	libavfilter/vsrc_color.c
Merged-by: Michael Niedermayer <michaelni@gmx.at>

* commit '73d5d405':
  split: switch to an AVOptions-based system.
Merged-by: Michael Niedermayer <michaelni@gmx.at>

* commit 'b13623e1':
  af_volume: switch to an AVOptions-based system.
Merged-by: Michael Niedermayer <michaelni@gmx.at>

* richardpl/biquads:
  lavfi/biquads: switch to an AVOptions-based system
Merged-by: Michael Niedermayer <michaelni@gmx.at>