output example: set the stream timebase

This is required by the new API.
output example: convert audio to the format supported by the encoder
hevcdsp: remove an unneeded variable in the loop filter

beta0 and beta1 will always be the same
hevc: SSE2 and SSSE3 loop filters

Additional contributions by James Almer <jamrial@gmail.com>,
Carl Eugen Hoyos <cehoyos@ag.or.at>, Fiona Glaser <fiona@x264.com> and
Anton Khirnov <anton@khirnov.net>

Signed-off-by: Anton Khirnov <anton@khirnov.net>
avcodec: Mark argument in av_{parser|hwaccel|bitstream_filter}_next as const
avformat: Mark argument in av_{i|o}format_next/ffurl_protocol_next as const
avformat: Mark AVOutputFormat argument in avformat_query_codec as const
eamad: use the bytestream2 API instead of AV_RL

This is safer and possibly fixes invalid reads on truncated data.

CC:libav-stable@libav.org
fate: support testing of release branches

Adding 'branch=release/10' to the fate config file will check the
release/10 branch instead of master. If no branch is specified it will
use 'master' so that existing config are still valid.

The server side changes are already deployed, see
https://fate.libav.org/v10/ for an example. The server supports only the
release/* branches.

The server enforces that a single slot tests always the same branch.
Please append "-v$RELEASE" to the slot of release branch configs or make
the slot otherwise unique.

A different fate samples dir is needed for each release branch. make
fate-rsync has the correct URL in each branch.
lavc: add a property for marking codecs that support frame reordering
codec_desc: fix some typos in long codec names

The rv20 typo spotted by Hendrik Leppkes <h.leppkes@gmail.com>
hevc: eliminate an unnecessary array

We do not need to store the value of the split flag.
hevc: simplify splitting the transform tree blocks
hevc: do not store the transform inter_split flag in the context

It does not need to be preserved.
hevc: eliminate unnecessary cbf_c{b,r} arrays

They are replaced by passing additional parameters to the transform
functions.
hevc: eliminate the last element from TransformTree

Replace it by passing an additional parameter to transform_unit()
video4linux2: Avoid a floating point exception

This avoids a segfault in avconv_opt.c:opt_target when trying to
determine the norm.
mxf: Detect Vanc/Vbi SMPTE-436M mxf track

Signed-off-by: Luca Barbato <lu_zero@gentoo.org>
mxf: Extract origin information from material and source track

Signed-off-by: Luca Barbato <lu_zero@gentoo.org>
configure: Use require_pkg_config for Speex

Distributors and integrators nowadays have less problems by leveraging
pkg-config files than having to set custom CFLAGS and LDFLAGS.