add the interfaces required to support rocshmem initialization
through the uniqueID mechanism. At the moment this still maps to
MPI initialization underneath the hood, but adding the functions might
simplify the porting of some applications to rocshmem. In addition, if
we need to transition away from MPI one day, this is also one step into
this direction.
* add team-barrier implementation
add a team-barrier API and implementation in the IPC and RO conduit.
Clean up some of the logic in the RO Conduit to distinguish between
sync, sync_all, barrier, and barrier_all.
* add team_barrier_tests to functional tests