Prevent cell from freezing if canSwipeToState returns NO
make the cell content not bounce when there are no buttons
do nothing if already in center state
set the cell state again after the scroll view is finished with scrolling because under certain circumstances the cell is centered but the state is not set to center
Merge pull request #93 from Alex9779/AppleStyle

make the cell content not bounce when there are no buttons
Merge pull request #92 from dacohn/scrolldisabledfix

Prevent cell from freezing if canSwipeToState returns NO
Merge pull request #94 from Alex9779/BehaviorOptimization

Behavior optimization