doc: Point to the correct, actually maintained gas-preprocessor repo

Signed-off-by: Martin Storsjö <martin@martin.st>
http: Properly initialize icy headers string

The icy_metadata_headers string never gets initialized, so,
during the first call to av_strlcatf() in parse_icy(),
strlen() will be called on a pointer to uninitialized memory.
At best this causes some garbage data to be left at the
start of the string.

By initializing icy_metadata_headers to the empty string, the
first call to strlen() will always return 0, so that data is
appended from the start of the string.

Signed-off-by: Luca Barbato <lu_zero@gentoo.org>
avconv: Match stream id

Quite useful to select by pid in MPEG-TS.
Prepare for 11_alpha1 Release
build: Drop stray mpc8 decoder dependency on dsputil
build: Drop stray PNG decoder dependency on dsputil
build: Drop stray MLP decoder dependency on dsputil
build: Drop stray MJPEG encoder dependency on dsputil
build: Drop stray LPC dependency on dsputil
ffv1: Drop bogus dependency on dsputil

ffv1 does not use any part of the dsputil framework.
configure: Add explicit dsputil dependency to mpegvideoenc

Previously, it was an implicit dependency through mpegvideo. Change
this, as implicit dependencies can cause all sorts of trouble.
build: Record dependency of eatqi decoder on dsputil
Remove all SH4 architecture optimizations

SH4 has been end-of-lifed and no more test machines are available.
Remove all SPARC architecture optimizations

SPARC is no longer being used in any multimedia-related fields and the
VIS optimizations only represent a maintenance burden.
x86: mpegvideoenc: Remove some remnants of the long-gone libmpeg2 IDCT
dsputil: Remove prototypes for nonexisting optimization functions
dsputil: Drop ff_check_alignment() function

The function is supposed to confirm that the compiler provided enough
alignment, but in practice it is only run in certain code paths and
insufficient alignment problems are restricted to legacy compilers.
dsputil: Move intreadwrite.h #include from header file to .c files
ppc: Add some missing headers
x86: Add some more missing headers