configure: msvc: Set the target windows version to XP if no target is set

MSVC 2010 (or more precisely, Windows SDK 7.0 which comes with MSVC
2010) sets _WIN32_WINNT to the constant for Windows 7 if nothing is
set. This could lead to the libav configure script detecting and
using functions only present in Windows 7 or newer, which in most
cases isn't desired. If the caller explicitly wants this, the caller
can add the _WIN32_WINNT define via --extra-cflags, setting the desired
version.

Signed-off-by: Martin Storsjö <martin@martin.st>
win32: Do not use GetProcAddress when compiled for Vista+

Instead link directly to the condition variable functions.

Signed-off-by: Martin Storsjö <martin@martin.st>
cmdutils: show timeline support in -filters listing
configure: add more allocation functions to valgrind-massif

Signed-off-by: Michael Niedermayer <michaelni@gmx.at>
vorbis: refactor vorbis_residue_decode_internal
vorbis: use normal integer values for iterators

No need to use fixed-size integers.
vorbis: simplify the inner loop in setup_classifs
vorbis: fallback to normal division instead of crashing

The use of ff_inverse speeds up slightly arches + compilers that
do not provide a division faster than the whole machinery, such
as ppc32 + gcc4.7, but has operational limits.

Drop the always-enable assert and provide a fallback.
mpegvideo: unref old current_picture before allocating a new one

Allows decoding with only three frame buffers with frame reference
counting. Fixes VAAPI based decoding in vlc which uses only three
frame buffers for the mpegvideo-based codecs.
avformat/matroskadec: fix integer overflow

Fixes fate-mkv with ekopath 4

Signed-off-by: Michael Niedermayer <michaelni@gmx.at>
lavd/v4l2: move pixel format conversion code to a separate place.

This will be shared with the output device.
lavd: add v4l2 outdev.
lavfi/geq: mark timeline support
md5: optimize second round by using 4-operation form of G()

4-operation form is preferred over 3-operation because it breaks a long
dependency chain, thus allowing a superscalar processor to execute more
operations in parallel.
The idea was taken from: http://www.zorinaq.com/papers/md5-amd64.html

AMD Athlon(tm) II X3 450 Processor, x86_64

$ for i in $(seq 1 4); do ./avutil_md5_test2; done
size: 1048576  runs: 1024  time:    5.821 +- 0.019
size: 1048576  runs: 1024  time:    5.822 +- 0.019
size: 1048576  runs: 1024  time:    5.841 +- 0.018
size: 1048576  runs: 1024  time:    5.821 +- 0.018

$ for i in $(seq 1 4); do ./avutil_md5_test2; done
size: 1048576  runs: 1024  time:    5.646 +- 0.019
size: 1048576  runs: 1024  time:    5.646 +- 0.018
size: 1048576  runs: 1024  time:    5.642 +- 0.019
size: 1048576  runs: 1024  time:    5.641 +- 0.019

Signed-off-by: Michael Niedermayer <michaelni@gmx.at>
Merge commit '0b6899f154347cdd0aa66c5ec16ed9c65871766f'

* commit '0b6899f154347cdd0aa66c5ec16ed9c65871766f':
  configure: msvc: Set the target windows version to XP if no target is set

Merged-by: Michael Niedermayer <michaelni@gmx.at>
Merge commit 'c360fb174b01170ab3fd3048d4d0acb44aa4e834'

* commit 'c360fb174b01170ab3fd3048d4d0acb44aa4e834':
  win32: Do not use GetProcAddress when compiled for Vista+

Merged-by: Michael Niedermayer <michaelni@gmx.at>
Merge commit '98186578a2a21af5bfe6dd71d222dc270f763c7d'

* commit '98186578a2a21af5bfe6dd71d222dc270f763c7d':
  vorbis: refactor vorbis_residue_decode_internal

Conflicts:
	libavcodec/vorbisdec.c

Merged-by: Michael Niedermayer <michaelni@gmx.at>
doc/filters: extend/fix documentation for the geq filter
doc/filters: add RGB geq example
Merge commit '36f10380043c8b8c5cbf8c1add8695089cdaa341'

* commit '36f10380043c8b8c5cbf8c1add8695089cdaa341':
  vorbis: use normal integer values for iterators

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