Remove a useless GPR flush when idle skipping

Patch from konpie: http://forums.dolphin-emulator.com/showthread.php?tid=24658
Avoid a test when writing a float to memory without the (disabled) SSSE3 implementation

Patch from konpie: http://forums.dolphin-emulator.com/showthread.php?tid=24658
Fix the psq_l implementation and re-enable it in the inst.W == 1 case

Patch from konpie: http://forums.dolphin-emulator.com/showthread.php?tid=24658
Replace the ps_sel Jit64 implementation and re-enable Jit for that instruction

Patch from konpie: http://forums.dolphin-emulator.com/showthread.php?tid=24658
Handle BP mask register better to avoid useless BP writes (causing flushes)

Patch from konpie: http://forums.dolphin-emulator.com/showthread.php?tid=24658
Implement the 4x4 matrix multiply with SSE2

Patch from konpie: http://forums.dolphin-emulator.com/showthread.php?tid=24658
Merge branch 'master' into misc-opts
Move FPRF update from end of each FP instr to FPSCR reads

Generates a lot less calls to MathUtil::ClassifyDouble in the most common cases
where FPSCR is not read after each FP instruction.
Use an unordered_set to track FIFO write adresses

Reduces CheckGatherPipe CPU consumption by 40%.
OS X C++11 support is a joke