Added a click/touch directional pad to impact++.

This is an alternative to the holdToMove and is managed by the PlayerManager. An example can be found in the jumpandrun example by uncommenting the section in the config-user.js

The dpad is placed on the screen when you do a holding touch and start to swipe in a direction, This should allow for you to control the player with one hand and use the other to tap to fire on the screen, without your fingers getting in the way of the view. And of course when you release the holding touch/click the dpad disappears from view.