rgmanager: Implement wait-for-fence behavior
    
    Changes to group/lib/Makefile are needed to make libgroup.so
    a shared object so as to not cause rgmanager to depend on a
    particular release of cman.  Changes to group/lib/Makefile
    mirror what cman/lib/Makefile does to create shared libraries
    
    This change implements a wait to ensure fencing has completed
    prior to services in rgmanager being allowed to start.  This
    is rhbz #459754