avcodec: Rename xvidmmx IDCT to xvid

The Xvid IDCT is not MMX-specific.
avformat/matroskaenc: fix MAX_CUEPOINT_SIZE calculation

Fixes assertion failure
Fixes Ticket3822

as a side-effect this makes some mkv files a few bytes smaller

Signed-off-by: Michael Niedermayer <michaelni@gmx.at>
Merge commit 'd35b94fbabd8beb5d566c0b5d01688aff62c3b36'

* commit 'd35b94fbabd8beb5d566c0b5d01688aff62c3b36':
  avcodec: Rename xvidmmx IDCT to xvid

Conflicts:
	doc/APIchanges
	libavcodec/version.h

Merged-by: Michael Niedermayer <michaelni@gmx.at>
avcodec/avdct: add "xvid" alias AVOption and use FF_IDCT_XVID

Signed-off-by: Michael Niedermayer <michaelni@gmx.at>
avformat/avio: Fix "warning: struct AVBPrint declared inside parameter list"

Signed-off-by: Michael Niedermayer <michaelni@gmx.at>
lavf/avio: do not include bprint.h.

See f75786f and 04bc370.
hevc: calculate the dbf strength in hls_pcm_sample() only if dbf is enabled
hevc_filter: drop redundant checks

ff_hevc_deblocking_boundary_strengths() is never called if the
deblocking filter is disabled for the slice.
hevc_filter: drop more redundant checks

The if() around those loops ensures this condition is always false.
hevc: deobfuscate slice/tile boundary handling for DBF

Use named constants instead of magic numbers, avoid using variables with
inverse meaning from what their name implies.
hevc_filter: move some conditions out of loops
hevc_refs: drop the handling of negative coordinates in ff_hevc_get_ref_list()

It makes no sense and cannot happen in any place from which this
function is called.
hevc_filter: avoid excessive calls to ff_hevc_get_ref_list()

1) each of the loops run within a single CTB, so the relevant reference
list is constant
2) when that CTB is, or lies on the same slice as, the current one, we
can use a simple access instead of a relatively expensive call to
ff_hevc_get_ref_list()
Postpone API-incompatible changes until the next bump.
Bump major versions of all libraries.
Remove obsolete FF_API_AVFRAME_COLORSPACE cruft.
Remove obsolete FF_API_PROBE_MIME cruft.
Remove obsolete FF_API_REFERENCE_DTS cruft.
lavc: remove obsolete and disabled avpriv functions
avfilter/dctdnoiz: remove a few indirections in idcts

No change in the generated asm.