This condition is important. `touchend` events can come following moves and other things that invalidate a straight-up-and-down tap, and the `tapping` flag is set on `touchstart` and cleared for those illegal motions.

As an example, without this, it's possible to put a finger down, move it two inches away, move it back so it's within the `MOVE_TOLERANCE` again, and release, triggering a tap.

Was this deliberately removed? If so, why? If not, please put it back when you squash into one commit.