x86: Remove X264_CPU_SSE_MISALIGN functions

Prevents a crash if the misaligned exception mask bit is cleared for some reason.

Misaligned SSE functions are only used on AMD Phenom CPUs and the benefit is miniscule.
They also require modifying the MXCSR control register and by removing those functions
we can get rid of that complexity altogether.

VEX-encoded instructions also supports unaligned memory operands. I tried adding AVX
implementations of all removed functions but there were no performance improvements on
Ivy Bridge. pixel_sad_x3 and pixel_sad_x4 had significant code size reductions though
so I kept them and added some minor cosmetics fixes and tweaks.
Fix AVX2 detection bug with "limit CPUID" enabled in BIOS
Fix a few minor bugs found with a static analyzer
Fix cases in which intra refresh allowed prediction from disallowed pixels
x86inc: Check for __OUTPUT_FORMAT__ having a value of "x64"

This is also a valid value for WIN64.
configure: Support cygwin64
x86: Faster AVX2 pixel_sad_x3 and pixel_sad_x4
x86: SSSE3 implementation of pixel_sad_x3 and pixel_sad_x4
Transparent hugepage support

Combine frame and mb data mallocs into a single large malloc.
Additionally, on Linux systems with hugepage support, ask for hugepages on
large mallocs.

This gives a small performance improvement (~0.2-0.9%) on systems without
hugepage support, as well as a small memory footprint reduction.

On recent Linux kernels with hugepage support enabled (set to madvise or
always), it improves performance up to 4% at the cost of about 7-12% more
memory usage on typical settings..

It may help even more on Haswell and other recent CPUs with improved 2MB page
support in hardware.
AVC-Intra support

This format has been reverse engineered and x264's output has almost exactly
the same bitstream as Panasonic cameras and encoders produce. It therefore does
not comply with SMPTE RP2027 since Panasonic themselves do not comply with
their own specification. It has been tested in Avid, Premiere, Edius and
Quantel.

Parts of this patch were written by Jason Garrett-Glaser and some reverse
engineering was done by Joseph Artsimovich.
Windows Unicode support

Windows, unlike most other operating systems, uses UTF-16 for Unicode strings while x264 is designed for UTF-8.

This patch does the following in order to handle things like Unicode filenames:
* Keep strings internally as UTF-8.
* Retrieve the CLI command line as UTF-16 and convert it to UTF-8.
* Always use Unicode versions of Windows API functions and convert strings to UTF-16 when calling them.
* Attempt to use legacy 8.3 short filenames for external libraries without Unicode support.
Fix GPAC support on Windows