Add SSE2 function for Inverse Cross-color Transform

Lossless decoding is now ~3% faster.

Change-Id: Idafb5c73e5cfb272cc3661d841f79971f9da0743
Add strong filtering intrinsics (inner and outer edges)

+ added some work-around gcc-4.6 to make it compile (except one function).
+ lots of revamping

All variants tested ok.
Speed-up is ~5-7%

Change-Id: I5ceda2ee5debfada090907fe3696889eb66269c3
Merge "Add strong filtering intrinsics (inner and outer edges)"