Enable mouseOver and mouseOut events.
MouseOver and MouseOut listener added only if present on serverside. Unit tests.
Merge branch 'feature/mouseOver' of github.com:Antea/v-leaflet into Antea-feature/mouseOver
Some improvements for mouseout/over listeners

 * avoid duplicate over events when modifying the vector that originated the event
 * added missing client side listeners for Marker
 * using helper to convert JS object to shared state object for client-server communication
Merge branch 'Antea-feature/mouseOver'