Unify mouse/touch interaction model using dojo/touch

[damiengarbarino]

Currently the calendar is native touchStart, touchMove and touchEnd events.
To be more generic, it could use the dojo/touch API
Problem: mixing Mouse and Touch will trigger issues as dojo/touch is reacting to mouse event.

[damiengarbarino]

The new dojo/touch philosophy is to unify mouse and touch interactions. So it's a bigger task I previously thought.
More a 2.0 task. Changing issue name.