Backport of 0ed7d155635da9f79d4dd67e4889087d3673c6da from master
Backport of 4669b6a807811d6763b9fdc5df974cb67aa1fb56 from master
Added support for PostgreSQL range types to contrib.postgres. - 5 new model fields - 4 new form fields - New validators - Uses psycopg2's range type implementation in python