Started unlock lighting file tool
Now saves and clears file after unlocking
Merge pull request #179 from melissaEdge/master

Unlock tool for shots in Houdini added
Changed mantra ROP defaults to use centered motion blur

This is more inline with the way that nuke does motion blur. In
case we choose to do motion blur in post instead of in camera,
it will be easier to make sure the renders match up properly.