Do not relay contextmenu and mousemove events

This PR is part of the ongoing effort from @fredj and I on improving the event handling and interaction code.

More specifically, this PR:

 * Removes the relay of contextmenu and mousemove events. Application code that wants to listen to native browser events should jQuery or similar, and use map.getEventPixel or map.getEventCoordinate to get the event position. The examples demonstrate this.

 * Emulates click and dblclick events on touch devices. With this change "click" is no longer fired when doing a double click to zoom on touch devices. We should have the same "click" behavior on mouse devices, but this will be done with a separate PR.

Please review.