x86: huffyuvdsp: Move inline assembly to init file

This avoids a link failure with MMX disabled as now code and
initialization are compiled under the same condition.
x86: Unconditionally compile blockdsp and svq1enc init files

This avoids a link failure with MMX disabled as the init functions
are referenced unconditionally.
x86: build: Only compile FDCT code if MMX is enabled

All other files containing purely inline assembly are treated the same way.
Merge commit '009331303a6462d07cbe94aef9c446f1a1695519'

* commit '009331303a6462d07cbe94aef9c446f1a1695519':
  x86: huffyuvdsp: Move inline assembly to init file

Conflicts:
	libavcodec/x86/Makefile
	libavcodec/x86/huffyuvdsp.h
	libavcodec/x86/huffyuvdsp_init.c
	libavcodec/x86/huffyuvdsp_mmx.c

Merged-by: Michael Niedermayer <michaelni@gmx.at>
avfilter/haldclut: fix R/B swap in CLUT loading

Fixes Ticket #3751.
Merge commit '12f129e545e5a5844b6ad7f3eb6a438015cad8bc'

* commit '12f129e545e5a5844b6ad7f3eb6a438015cad8bc':
  x86: Unconditionally compile blockdsp and svq1enc init files

Conflicts:
	libavcodec/x86/Makefile

blockdsp_mmx is renamed to blockdsp_init as we already have a blockdsp file
and _init is how all other such files are called

Merged-by: Michael Niedermayer <michaelni@gmx.at>
Merge commit 'b0de1c766329dd8c9960ad1722e2f653160abc1b'

* commit 'b0de1c766329dd8c9960ad1722e2f653160abc1b':
  x86: build: Only compile FDCT code if MMX is enabled

Conflicts:
	libavcodec/x86/Makefile

Merged-by: Michael Niedermayer <michaelni@gmx.at>
x86/svq1enc: port ssd_int8_vs_int16 to yasm

Also add an SSE2 version

Signed-off-by: James Almer <jamrial@gmail.com>
Signed-off-by: Michael Niedermayer <michaelni@gmx.at>
avcodec/old_codec_ids: workaround doxygen inclusion bug

Currently, http://ffmpeg.org/doxygen/trunk/group__preproc__misc.html is
broken, because of inclusion bug in Doxygen's preprocessing mode. The
now-unincluded header file is included anyway in avcodec.h, the only
place where it is used, so there should be no problem removing it.

One concern is API-compatibility, because old_codec_ids.h is a public
header. However, IMO this is not a problem because currently users
cannot include only this header and not `avcodec.h` anyway, because of
missing AV_CODEC_ID_NONE symbol.

Signed-off-by: Timothy Gu <timothygu99@gmail.com>
Signed-off-by: Michael Niedermayer <michaelni@gmx.at>