it's a much simpler structure now
removed: FieldValueBase and FieldValueContainer
git-svn-id: svn://ttmath.org/publicrep/morm/trunk@1207 e52654a7-88a9-db11-a3e9-0013d4bc506e
for setting a parent key id in child models,
it is called after after_insert() method
added: SetFieldValueHelper class used for storing primary key values from a parent model
git-svn-id: svn://ttmath.org/publicrep/morm/trunk@1204 e52654a7-88a9-db11-a3e9-0013d4bc506e