Added touch support and partial pinch zoom support

[gavJackson]

Can now interact with the globe on a touch device using simple gestures to manipulate the globe. I implemented mouse event simulation triggered by touch events (like how jquery touch punch works).

I also attempted to implement pinch zooming, which works well in Android but not so well in iOS (due to Safari having weird inbuilt gestures to see an expose of tabs) - so the pinch zooming is off by default, but can be turned on through opts.pinchZoomEnabled=true

[texastoast33]

+1

[oshopgiri]

It works magic :+1: Thank a ton @gavJackson

[CollioPHP]

I feel this needs a push and someone with an ios device should test thisagain. After this years it should work :)