Fix inter non-determinism with tiles
Fix inter non-determinism with tiles

CU data was being copied to the wrong place in the reference frames
cu_array, which led to uninitialized data being used as a starting
point for motion vector search.

Fixes #99.

ultravideo/kvazaar,ultravideo/kvazaar,ultravideo/kvazaar,ultravideo/kvazaar,ultravideo/kvazaar