intra: fix GCC warning about potentially uninitialized sum variable
common: force float and double arguments to logf() and log(), respectively

Fixes warnings on some MSVC versions
asm: add cvt32to16_shr_sse2, remove intrinsic primitive
asm: fix 32bit build following partition enum carnage
intra: remove unused variable
intra-sse3.cpp: replace xPredIntraAng4x4 vector class function with intrinsic.
blockcopy-sse3.cpp: removed warning: overflow in implicit constant conversion.