Prior to this commit roaming geofences only registered changes to
the SET command. Now it will work for SET/DEL/FSET, just like
non-roaming geofences.
To opt out of these events, explicitly choose which event you
would like to register when you create the geofences.
For example:
NEARBY fleet FENCE COMMANDS set,del ROAM fleet * 5000
Will only fire off events from SET and DEL command.
Closes#597
b5691f7dd5