Remove the proc_pml and proc_bml fields from ompi_proc_t and replace with a
configure-time dynamic allocation of flags.  The net result for platforms
which only support BTL-based communication is a reduction of 8*nprocs bytes
per process.  Platforms which support both MTLs and BTLs will not see
a space reduction, but will now be able to safely run both the MTL and BTL
side-by-side, which will prove useful.