tt#1784: fix MPL_VG_ macros with valgrind 3.6.0

Reported and largely debugged by Chris Daley (thanks!).

fixes #1784

No reviewer.
Added gtags files to .gitignore
Merge branch 'master' of git.mpich.org:mpich
Replaced printf with DBG_MSG
added DBG message for memcopy
Fix error handling bug for struct datatypes

Reviewer: goodell
Fix poor error handling in RMA code
tt#1785: NBC progress issues with ch3:sock

We made progress for MPI_Wait and friends, but not
MPI_Test/MPI_Iprobe/etc.  Thanks to Jed Brown for letting us know about
this issue.

fixes #1785

Reviewed-by: buntinas
tt#1785: add a symbol for configure testing

Should allow PETSc to decide whether or not they can safely use
nonblocking collectives with ch3:sock.

Reviewed-by: buntinas
tt#1786: set MPID_MAX_THREAD_LEVEL in ch3:sock correctly

fixes #1786

No reviewer.
fix TAP output when test prog fails to build

fixup for 51b7260

No reviewer.
TAP: add "# SKIP" directive support

This way tests that were skipped because of strictness or version
constraints will show up in the summary.tap output file.

Reviewed-by: dinan
runtests: permit arbitrary capitalization in args

At Jim's request...

Reviewed-by: dinan
TAP: add "xfail" support

This is used to indicate tests that are correct, but functionality that
is expected to fail in the current version of the MPI implementation.
This is expressed in `testlist` files with an argument string like
`xfail=ticketXYZ` or `xfail=REASON` after the program name.
Unfortunately, spaces, quotes, and `#` characters are not permitted in
the format at this time, due to the primitive nature of the testfile
parser code.

If strict MPI testing is requested (by configuring the test suite with
`--enable-strictmpi`) then the `xfail=BLAH` arguments are ignored under
the assumption that they are only accurate for the current version of
the MPICH implementation.

No xfail support has been added to the XML output at this time.

Reviewed-by: dinan
add `xfail=ticketXYZ` annotations to failing tests

These five tests are currently failing on a regular basis with MPICH.
All need to be dealt with at some point, but we cannot fix them right
now and they make it hard to spot new failures in the tests.

references #1767, #1788

Reviewed-by: dinan
move MPI_T tests to their own subdir in "manual"

Reviewed-by: rgunter
MPI_T_pvar_read/write now respect the handle creator's count variable
Add MPIT variables and corresponding tests.

The following MPIT performance variables are added:

 - nem_fbox_fall_back_to_queue_count;
 - time_failed_matching_postedq;
 - time_matching_unexpectedq;
 - unexpected_recvq_buffer_size.

Some common MPIT-related routines, handle creation functions and
enable/disable switches are gathered in a common file.

Two test cases are furnished, but not yet integrated with 'make check'.
Add configure args to selectively enable MPIT pvars.

Users can now pass --enable-mpit-pvars to configure to statically
enable/disable MPIT performance variables so as to limit performance
impacts only to those variables they need.

Current valid arguments are as follows:
    none     - No performance info recorded
    recvq    - All message queue-related variables
    nem      - All nemesis-related variables
    all      - All variables above

A macro framework is added to facilitate the addition of new variables
(see MPIR_T_GATE on mpid_common_statistics.h).

Also add a check to the MPIT nemesis test to ensure that the variables
being tested have been registered with the runtime.
fixup for new pvar build system code

Reviewed-by: rgunter