Modify the tap gesture recognizer to be more like the UITapGestureRecognizer where we:

* allow consecutive taps to fire several events, ie. requiring 3 taps but tapping 6 times results in 2 recognitions
* use a different timeout when we're waiting for a tap to complete (750ms) and for the next tap to start (350ms)
* make the taps count a private ivar
Rename entered to enter since the state hasn't changed yet.