fix weighted unweighted
Merge branch 'hevc' of https://github.com/OpenHEVC/openHEVC.git into
hevc

Conflicts:
	libavcodec/x86/hevcdsp_init.c
moved weighted functions to SSE4
clean clang error
Merge branch 'hevc' of https://github.com/OpenHEVC/openHEVC.git into hevc
added prefetch instruction
Merge branch 'hevc' of https://github.com/OpenHEVC/openHEVC.git into hevc
removed all XPEL_W functions
added small optimisation in EPEL_V_compute
changed some unpacklo to cvtepi
added more cvtepi to replace unpack + srai
change _mm_cvtepi8_epi16 into _mm_cvtepu8_epi16
update