Add Contact.get_or_create_from_urn() to return a contact by urn
Add Contact.get_or_create_from_urn() to return a contact by urn

rapidpro/casepro,rapidpro/casepro,xkmato/casepro,rapidpro/casepro,praekelt/casepro,xkmato/casepro,praekelt/casepro,praekelt/casepro