Add automember rebuild command
    
    Add a new command to IPA CLI: ipa automember-rebuild
    
    The command integrates the automember rebuild membership task functionality
    into IPA CLI. It makes it possible to rebuild automember membership for
    groups/hostgroups.
    
    Design: http://www.freeipa.org/page/V3/Automember_rebuild_membership
    https://fedorahosted.org/freeipa/ticket/3752