x86: sbrdsp: implement SSE qmf_deint_bfly

From 312 to 89/68 (sse/sse2) cycles on Arrandale and Win64.
Sandybridge: 68/47 cycles.

Having a loop counter is a 7 cycle gain.
Unrolling is another 7 cycle gain.
Working in reverse scan is another 6 cycles.

Signed-off-by: Michael Niedermayer <michaelni@gmx.at>
dynamic loading of shared faac library
avfilters: better behavior of frei0r on win32
programs: print version info and configuration only on -version
configure: fix modplug detection (it needs +lstdc++)
no Werror on implicit-function-declaration and missing-prototypes
configure: don't add -fPIC on MinGW-w64
custom icon and windows resource
use upstream version tag, my repo is always rebased
Add thread-safe wrapper for get_format().

Just like get_buffer, get_format should not be called from a different
thread if thread_safe_callbacks is not set.

Signed-off-by: Reimar Döffinger <Reimar.Doeffinger@gmx.de>