Form: inserting a hidden input with the geo coordinates if a
spot isNew(). The geo coordinates are required by the backend
in order to persist a new spot. For this we're overriding
Marionette.ItemView#serializeData() to inject isNew as a simple
property for the handlebars template as its #if helper doesn't
call functions.

There was a field calld "location" before which was serving as a
reverse geocoding query field with which you could refine the
placement of the spot. This field is now called "location_query".