Type labels

Updated naming of labels such that JDBC returns our type labels instead of Postgres type labels when using rs.getMetaData.getTypeName().

Some types remain special:
- Due to the OID type central approach of our JDBC driver Decimal was resolved to a Unsigned Bigint as this uses the same oid value, this is fixed by 'order by clause' in TypeInfoCache#createFDBNameStatement(). 
- uuid/GUID is only available from jdbc3g, and is handled at the original location. A major clean-up of the JDBC driver would be nice, removing all facilities for postgres compatability. 
- json type (oid = 114) would not be resolved in the standard manner, but is necessary for output format json, new type resolving would fails if output format is set to json.




jdbc_type_id isn't used.

I might suggest something like excluding types with UNSIGNED in the name. Still a hack but slightly more obvious.