asm: modified common macro for pixel_sad_64xN
asm: assembly code for pixel_sad_64x16
asm: assembly code for pixel_sad_64x32
asm: assembly code for pixel_sad_64x48 and pixel_sad_64x64
asm: filterConvertPelToShort
asm: assembly code for pixel_sad_48x64
asm: assembly code for pixel_sad_24x32
asm: assembly code for pixel_sad_12x16
assembly code for pixel_sad_x3_24x32
assembly code for pixel_sad_x4_24x32
assembly code for pixel_sad_x3_32xN
assembly code for pixel_sad_x4_32xN
pixel: remove 24 and 32 width sad intrinsic functions

These are now covered by assembly.  Only 12, 48, and 64 remain because they
still lack x3 and x4 versions.
pixel: remove sad_12, sad_48, and sad_64

All single sads have asm coverage
added test code for blockcopy_pp function
added blockcopy_pp_c primitive according to modified argument list