center_smash improvements
center_smash improvements

* `smash_to_center` case must return left and right offets
* greatly improved `smash` performance by counting zeros in the foreground mask instead of doing unnecessary numpy "fancy indexing" of the image
* identified broken case: when ONE side is in the central quadrant and the other side is in the outer quadrant. The `smash` closure function doesn't behave correctly for this case.

TadLeonard/crash-kiss,TadLeonard/crash-kiss,TadLeonard/crash-kiss