HierMemDirCtx uses object factories when it is doing a subtree search.
It shouldn't be doing this when it is representing an LDAP schema tree
because that might affect the correctness of operations on the schema tree.

Furthermore, HierMemDirCtx is also used by the DSML provider which
does require object factories be used for certain operations.

HierMemDirCtx should be fixed so that it is easily configurable
to handle factories or not.