Fixes #3591: Move r28439 to v1.7 branch (MPI-2.2 COMM_SELF attribute destruction ordering)

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r28439 [[BR]]
Implement MPI-2.2 functionality of deleting attributes on
MPI_COMM_SELF in reverse order during MPI_FINALIZE (well, actually,
''all'' attributes are now deleted in reverse order whenever a
communicator is destructed).

Also revamped a few things in the MPI attribute implementation:

 * use a One Big Lock philosophy for making the implementation thread
   safe (vs. the pair of locks we were using before).  One Big Lock is
   quite a bit simpler and has fewer corner cases; the code for
   attributes is still complicated, but is definitely less complex
   than it used to be.
 * The COPY_ATTR_CALLBACKS and DELETE_ATTR_CALLBACKS macros no longer
   return; they simply set a value if something went wrong.  Then we
   check this value after the macros complete.  This simplifies
   unlocking, etc.
 * Added write barriers right before releasing locks to ensure memory
   consistency.
 * Fixed a bunch of typos in comments, and some indenting.

Many thanks to KAWASHIMA Takahiro who contributed the original patch
for attribute destruction ordering, and who helped test/debug/evolve
the patch to its final form.

Fixes #3123.

cmr:v1.7.2:reviewer=bosilca
Fixes #3588: Move status fixes to v1.7

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r27403 [[BR]]
Ensure that MPI_Status objects have proper alignment:
- fix the Fortran layer to use new macros to convert Fortran-to-C status
- change the C internals to pull out old OMPI_SET_STATUS* macros

Also, change name of "status" argument in topo_test_f.c to "topo_type".


r28431 [[BR]]
Correctly handle the invalid status for null and inactive
requests. This patch fixes #3475.

CMR v1.6, v1.7
Fixes #3602: Move r28489 to v1.7 branch (register MXM to memhooks)

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r28489 [[BR]]
Fix data corruption in MXM by registering to OPAL memory release hooks and removing any mappings created by mxm
Bump to 1.7.2rc1
Set svn:ignore
Add missing header file from #3588 / r28507