Merge commit '9047491f8bcd87673eed55fb310647a03b0981e9'

* commit '9047491f8bcd87673eed55fb310647a03b0981e9':
  swscale: add nv12/nv21->yuv420 converter

Conflicts:
	libswscale/rgb2rgb.c
	libswscale/rgb2rgb_template.c

See: ef627bf9ecddfa888d4c6e4fd633852798c3b4a9
Merged-by: Michael Niedermayer <michaelni@gmx.at>

diff --cc libswscale/rgb2rgb.c
Simple merge

diff --cc libswscale/rgb2rgb_template.c
Simple merge