Handle touch cancellation / touch up away from button correctly

[apptekstudios]

Hi @simonbs, nice library. Very useful to save reimplementing this.

I noticed you weren't able to cancel a button press by moving away from the button (as also mentioned in #1 )

This is a simple patch to only run the representativeTool action if 'touchUpInside' was fired (rather than outside as well). It should not affect behaviour of the sub-tools.