Support touch event identifiers properly

The specification for the identifier of a touch event does not enforce that the identifier is sequential for the number of touches, only that it is a long unique amongst all other active touch points

This patch adds support for any identifier not just sequential ones

Also note that there was a bug in createAllFingerData that assigned identifier:0 rather than identifier:i

(see http://www.w3.org/TR/touch-events/#attributes)