isIconVisibleOnClick now is a local var to. Injecting into scope in a
directive is not angular apparently.
marker.icon is now watched via scope inside a marker directive
- on value change the google.marker's icon will be set
- marker will be removed from the map and then readded in the same
  position.
closeClick needs to be tracked if you are using markers.show on a perMarker basis, especially if you are only trying to allow one Window at a time.[C
Merge pull request #60 from trafficland/feature/icon_update_without_destroy

Feature/icon update without destroy