Add missing BOOST_FORCEINLINE for direct element access
refactoring script complete, needs testing and implementing macros correctly
avx shufle specialization corresponding to _mm256_unpack_lo/hi added  #844
clang emit a run time overflow on signed integer product in the cas of unsigned short.
this is a workaround and some added test to see if multiplies properly wraps for unsigned types
adding #ifdef __clang__ to unsigned short multiplies bug workaround