Toucher Gremlin

I've created a touch gremlin, that can trigger (multi)touch gestures. The example uses Hammer.js to verify what touchevents/gestures are being triggered.

As discussed in https://github.com/marmelab/gremlins.js/issues/40.
Demo: https://rawgithub.com/jtangelder/gremlins.js/master/examples/touch/index.html