TAP: comply better with "TAP Version 13"

The "TAP Version 13" specification (normally available at
http://testanything.org/wiki/index.php/TAP_version_13_specification but
currently only available via the Wayback Machine) does not actually
permit spaces before a comment line.

It also requires a special string at the beginning of the file to
indicate that YAMLish should be expected.  Otherwise, TAP::Parser will
pretend not to see the YAML blocks.

No reviewer.
Fix typo introduced in dd76a0f that's causing the nightly tests to
fail.

No reviewer.
Improvements to the release.pl script.

1. The release.pl creation script now takes a remote git repository as
an argument instead of a local clone.  This allows this script to be
standalone and not rely on the copy used by the nightly scripts.

2. Allow release.pl to abort if no recent commits have been pushed to
the repository.

3. Simultaneously create both the main tarball as well as the hydra
tarball.

4. Renames of some arguments to better match what they are referring
to.

Reviewed by goodell.
add `pipestatus` shell helper

This will simplify some of our Jenkins configurations.  All this commit
does is stash a copy of `pipestatus` in `maint` from
https://github.com/cheusov/pipestatus.

No reviewer.
Squash ARMCI-MPI build warnings
Make kvs_name and kvsname consistent.

No reviewer.
Added ability to allgather codes to all the proxies during a PMI
barrier.  This allows all gets of the keys to occur locally without
having to communicate with the mpiexec process.

Also, got rid of unscalable parsing code as well as incorrect tmp
length usage without checking for how many arguments were actually
passed between the proxy and mpiexec.

No reviewer.
Cleanup memory allocation for the keyvals being forwarded to the
proxies, so we don't do the allocation for each proxy -- it's the same
data sent to all proxies.

No reviewer.
CHANGES file updates for Hydra.

Added a note describing the new scalability improvements with
key/value caching.

No reviewer.
Update mpich release and ABI versions for the 3.0.4 release.

No changes were made to mpi.h or the Fortran bindings, AFAICT.  Only
incrementing the revision ('r') field for the ABI string.

Reviewed by goodell.
Move folks who are no longer contributing to the MPICH code to the
"past contributors" list and add the new group members to the current
contributors list.

No reviewer.
Warning squash: unused variables.

No reviewer.
Bug-fix: PMI keyval allgather code.

When we overflow our flow-control packet size and send multiple
packets of keyval pairs, we were overwriting the older information.
Discovered by artificially making the flow-control size very small.

No reviewer.
Single-quotes are used for manpage formatting.

Move additional characters that are not a part of the MPI function
name outside the single-quoted domain, since they are used for manpage
formatting by doctext.

Reviewed by dinan.
Yet another bug-fix in the commenting out the performance tests from
[dd76a0f2].

No reviewer.
Improve [480baf02] with Dave's suggestion.
delete more "relative" svn:externals dirs

Specifically:
* `src/armci/m4/`
* `test/mpi/confdb/`

These directories were missed in [6ef688f1] for some reason.

No reviewer.