Show cursor coordinates on map

[tomvantilburg]

Coordinates in current system (and/or WGS84)

[MartijnHeuff]

Added in #254

[MauriceWillekens]

Tried to test in Chrome but could't see the cursor coordinates in the map. Used: http://research.geodan.nl/sites/icm-ui/#/incidenten/1404726678734/summary/kaart