Experimental LDAP Prepwork

* A "unit" is a dept/group/etc that wants to use this xldap "thingy"
  (eg, Physics)

* The unit must already have its own GWS stem/space: uw_UNIT
  (eg, uw_phys)

* The unit creates the GWS group uw_UNIT_unix_users
  whose (effective) membership is its list of unix users
  (eg, uw_phys_unix_users)

* For each desired unix group GROUP, 
  the unit creates the GWS group uw_UNIT_unix_group_GROUP
  whose (effective) membership is the desired user membership
  (eg, uw_phys_unix_group_nuc-thy, uw_phys_unix_group_nuc-exp, ...)

* The unit then requests an xldap branch for their use,
  specifying what their GWS stem is (uw_UNIT)