[RM plugin]
Fix MPICH2 and Intel MPI support:
1. Handle some srun short and long options to support Intel MPI.
2. Fix PMI support to handle Intel MPI.



git-svn-id: svn://svn.code.sf.net/p/dmtcp/code/trunk@2722 ba6dc0ae-232f-0410-883f-9ebac64fc565