Add Neighborhood to a Location via foreign key relation. Import scripts keep the two synced when either is readded. 

Added:
+ Neighborhood foreign key referench to Location
+ A Location updates its Neighborhood when it is saved to the database
+ Read-only field in admin view displays the Neighborhood for a Location
+ Updates to the manage.py import and manage.py load_neighborhood commands to keep the two objects in sync when either is reloaded