scale columns ported to SSSE3 BUG=208 TESTED=runyuv Scale*640* Review URL: https://webrtc-codereview.appspot.com/1292004
scale columns ported to SSSE3
BUG=208
TESTED=runyuv Scale*640*
Review URL: https://webrtc-codereview.appspot.com/1292004
flykickbird/libyuv,flykickbird/libyuv,flykickbird/libyuv