add helper classes


git-svn-id: svn+ssh://svn.gna.org/svn/gnustep/libs/sqlclient/trunk@36261 72102866-910b-0410-8b05-ffd578937521
1.6.0 release


git-svn-id: svn+ssh://svn.gna.org/svn/gnustep/libs/sqlclient/trunk@36262 72102866-910b-0410-8b05-ffd578937521