Blender Git Loki

bicubic_interpolation - dont use pow(val, 3.0f) at all, do (val*val*val) instead,
Tested overall speedup is about 5x when scaling 4096x4096 -> 4000x4000 in the sequencer.

There were some artifacts in the resulting image but double checked and the old code gives the same problems.
Added back old code with #if 0's since its a bit more readable.