Continue to tune
TestBed build pass.
link to glut on ubuntu 12.04
Use unalinged since LLVM generated code crash on movaps
Bug fixing.

TODO=b2MathTest
Fix vector multiply bug.
Fix another bug in b2Math
Use accessor in Bench2d
Another fix of b2Math.

Pass TestBed.
Add v2MathTest for unit test.
Support SIMD or non-SIMD build