def registerMemberData(m, id):
    """ Add the given member data to the _members btree.

        o 'm' is an object whose attributes are the memberdata for the member.

        o 'id' is the userid of the member.

        o Add the record late as possible to avoid side effect transactions
          and to reduce the necessary number of entries.

        o ???: these argument names are silly;  can we use more sensible
          ones (i.e., does anyone actually depend on them)?

        o Permission:  Private (Python only)
        """
