When centerHiddenInteractivity changes with any side open, the centerTapper should be removed / added
(Re)Added check for in-flight preview bounce animation when panning starts, and a more graceful transition to if animation is in progress.
passing back affected controller for side in completion selectors instead of leftController
Merge pull request #256 from robby/master

sending correct controller to delegate selectors in completion blocks
Merge pull request #251 from cbpowell/previewBounce

Mid-bounce panning fix
Merge pull request #248 from wamballi/master

Update centerTaper when centerHiddenInteractivity changes