Add many, many missing types to PostgresDataType (#371)

* Add lots of missing PSQL type codes and element/array type mappings, including geometry types, the reg* types, network address types, many missing array types, bit and varbit, the pseudo-types, text search types, more range types, jsonpath, and the multirange types.

* More clearly document where the list of types etc. came from.

Author: gwynne