This fixes a problem in ResultSet.getDate() when the column is NULL
(reported by Vincent Partington <Vincent.Partington@nmg.nl>)
And fixes a problem with Field's (ResultSet.getObject() was proving to be
slow as it repetedly send queries for oid -> name mapping - fixed by
creating a cache. (reported by Mario Ellebrecht <ellebrec@nads.de>)
Ok, this fixes three things:
1. It seems (from tests submitted by two people with JBuilder) that
JBuilder expects a responce from ResultSetMetaData.getPrecision() &
getScale() when used on non numeric types. This patch makes these
methods return 0, instead of throwing an exception.
2. Fixes a small bug where getting the postgresql type name returns null.
3. Fixes a problem with ResultSet.getObject() where getting it's string
value returns null if you case the object as (PGobject), but returns
the value if you case it as it's self.
