Added type-specific field accessors to db_object interface.
Modified client to use new type-specific db_object field accessors
Modified PasswordClient to use type-specific db_object field accessor
Got rid of duplicative getFieldDef() methods on DBObjectBase, removed needless casts
Removed needless casting for DBSchemaEdit getBase() and createNewBase()
Got rid of a bunch of unneeded DBObjectBaseField casts
Took out a redundant cast in DBLog.updateObjEventCodeHash()
Renamed DBObject containsField() to hasField()