Add a gaMapClick service

This service allows registering map click handlers that work on mouse, touch and pointer devices.
Make tooltip directive use gaMapClick
Extend browser sniffer to detect webkit and mac
No tooltip query if mouse button is not action
No identify queries on long press
Change timeout for click to be considered single
Use stopEvent true for the context popup
Merge pull request #620 from geoadmin/fix_tooltip

Double tap/click to zoom in makes 2 identify request.