Fixes #3752: Move proc-tags change to v1.7

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r29100 [[BR]]
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.
Fixes #3761: Build fails with --without-threads

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r29145 [[BR]]
fixed build without thread support