sparc: VIS mnemonics

Currently, if VIS is enabled by configure, it will also be enabled at
run-time regardless of its support in the hardware. Thus, masking VIS
usage as it is done in vis.h by constructing binary instructions is
pointless. Using normal VIS mnemonics in inline assembly allows to take
advantage of automatic register allocation, gets rid of register
variables, which are unsupported by suncc for SPARC, and improves code
readability.

Signed-off-by: Diego Biurrun <diego@biurrun.de>
jpegls: return meaningful errors
jpegls: factorize return paths
jpegls: check the scan offset

Prevent an out of array bound write.

Reported-by: Mateusz "j00ru" Jurczyk and Gynvael Coldwind
CC: libav-stable@libav.org
lavfi doxy: add a page for lavfi.
doxy: add a section about versioning.
lavc doxy: add avcodec.h to the libavcodec group.
lavr doxy: add version.h to the lavr group
doxy: don't sort struct members alphabetically

The declaration order is more meanigful in most cases.
lavfi: rename AVFilterFormats.format_count to nb_formats

This is more consistent with naming in the rest of Libav.
af_aformat: cosmetics, fix indentation
vf_format: do not use the AVFilterFormats internals.

Use the formats.h API instead.
lavfi: factorize freeing a link
avfilter.c: cosmetics, reformat
avfilter: check a malloc in avfilter_link().

Additionally change sizeof(type) into sizeof(var)
prores: decode alpha plane when it's present
Escape 130 (RPL) decoder

Some fixes provided by Paul B Mahol <onemda@gmail.com>
and Michael Niedermayer <michaelni@gmx.at> and me.

Signed-off-by: Diego Biurrun <diego@biurrun.de>
Signed-off-by: Kostya Shishkov <kostya.shishkov@gmail.com>
wavpack: K&R formatting cosmetics

Signed-off-by: Diego Biurrun <diego@biurrun.de>
wavpack: return meaningful errors

And forward those that were already meaningful.
wavpack: validate samples size parsed in wavpack_decode_block

Reported-by: Mateusz "j00ru" Jurczyk and Gynvael Coldwind
CC: libav-stable@libav.org