Move declaration of PlanningAlerts js global into end matter

So that every javascript can assume it's existence automatically
Move map styles into a separate js file

So that they can be shared between different pages,
this places them into a property on the global PlanningAlerts
object for easy re-use
Allow initialiseMaps to receive extra options

So that we can pass things like styles into the map construction
functions
Use Hampshire map styles on the application page