Create SSE type header

[vhirtham]

• [x] Create a header with #include <x86intrin.h> and the definitions to ignore gcc warnings
• [x] Include header everywhere else instead of #include <x86intrin.h>
• [x] rename namespace sse to namespace simd
• [x] rename sse folders to simd
• [x] rename classes with variable register type to ...SIMD (VecSSE -> VecSIMD)
• [x] rename intrinsics.h to intrinsicTemplates.h
• [x] rename all intrinsic templates as follows: _mmx_mul_p -> _mm_mul

[vhirtham]

Finished with commit 0c31e46bf13d05e2ccda1523ec770e481b9e4b54