Per patch from Tetsuya, allow the user to bind-to none when specifying multiple pe's/rank as requested by Reuti. This allows the user to reserve multiple "slots" in the allocation for each process while mapping, but not to bind the process to specific processing elements on the node.

Reviewed by rhc, so RM-approved to go across to v1.8.3

cmr=v1.8.3:reviewer=ompi-gk1.8