Applied two patches from Kris Jurka.

  - First fixes a problem with a recent patch allowing setNull on updateable
    resultsets
  - Second removed toLower() calls on database object names.  Leave it to
    the caller to correctly pass lower, upper or mixed case.  The driver
    already has methods that the caller can use to determine that postgres
    stores identifiers in lowercase. (unless the identifier was quoted when
    created).

 Modified Files:
 	jdbc/org/postgresql/jdbc1/AbstractJdbc1DatabaseMetaData.java
 	jdbc/org/postgresql/jdbc2/AbstractJdbc2ResultSet.java