YUV 411 is very uncommon format.  Remove support.

Update documentation to reflect that 411 is deprecated.

Simplify tests for YUV to only test with the new side by side YUV but keep old 3 plane test around with a macro for now.

BUG=libyuv:645
R=kjellander@chromium.org

Review URL: https://codereview.chromium.org/2406123002 .