Panzer: Fixing construction of coordinates for MueLu

The dimension wasn't updated propertly when setting the coordinate
array in the multi-vector. Thus Zoltan2 was partitioning a line
as opposed to a 3D array...yikes!
MueLu: another test update
Zoltan2: AlgPQJagged - added one more ifdef for migration flag.
MueLu: easy: added -B flag to diff cmd to ignore blank lines
Tpetra: MultiVector: op=: Relaxed debug mode compatibility check.

MultiVector's assignment operator (operator=) does a deep copy.  It only
needs the local dimensions on each process to match.  However, in debug
mode (HAVE_TPETRA_DEBUG), the method was checking for compatibility of
the two MultiVectors' Maps.  This is a more restrictive condition, since
it requires the Maps' communicators to ahave the same numbers of
processes.  That prevents use of operator= for when one MultiVector has
a "local communicator" (MPI_COMM_SELF or the equivalent
Teuchos::SerialComm) and the other a "global communicator" (e.g.,
MPI_COMM_WORLD), but the dimensions match.  (This case comes up in
Ifpack2 when using LocalFilter for things like domain decomposition.)
As long as operator= is called collectively over the "larger
communicator," the operation makes sense.  Thus, I changed the debug
mode check so that it only checks whether the dimensions match on all
processes.

Build/Test Cases Summary
Enabled Packages: Ifpack2, Xpetra, MueLu, Amesos2
Disabled Packages: MOOCHO,NOX,Rythmos
Enabled all Forward Packages
0) MPI_DEBUG => passed: passed=231,notpassed=0 (5.68 min)
1) SERIAL_RELEASE => passed: passed=201,notpassed=0 (0.58 min)
MueLu: Graph: added string type validator to CoalesceDropF
MueLu, Xpetra: fixed multiple warnings, mostly [-Wshadow]

Xpetra declared

   typedef Teuchos::ScalarTraits<SC> ST;

in the global namespace, which resulted in multiple shadow warnings, as
Teuchos used same typedef in its functions. I removed that typedef, and
fixed resulting issues in MueLu.
MueLu: MLParamInterpreter: fixed unused variable warnings
MueLu: allow "classical" value for algorithm validator
MueLu: updated easy tests (reordered params)
Ifpack2: Added new subdomain solver for testing AdditiveSchwarz.

Writing AdditiveSchwarz tests is easier if you have an exact subdomain
solver.  Ifpack2::Details::DenseSolver uses LAPACK's LU factorization
(GETRF and GETRS) to solve subdomain problems.  Like Ifpack2::ILUT, it
has a built-in LocalFilter, so you can use it directly as a
preconditioner.  (Without an AdditiveSchwarz wrapper, this would make
DenseSolver equivalent to nonoverlapping additive Schwarz domain
decomposition.)  Of course, it's a _dense_ solver, so you shouldn't use
it for large problems.  Its main purpose is for AdditiveSchwarz tests.

MueLu: Fixed syntax error that only appears when ML is disabled.

Alas, it's hard to test all possible combinations of disabled packages.
However, this was an obvious syntax error, so I thought it safe to
correct.

Build/Test Cases Summary
Enabled Packages: Ifpack2, Xpetra, MueLu, Amesos2
Disabled Packages: MOOCHO,NOX,Rythmos,ML
Enabled all Forward Packages
0) MPI_DEBUG => Test case MPI_DEBUG was not run! => Does not affect push readiness! (-1.00 min)
1) SERIAL_RELEASE => Test case SERIAL_RELEASE was not run! => Does not affect push readiness! (-1.00 min)
2) MPI_DEBUG_SS => passed: passed=123,notpassed=0 (3.61 min)
3) SERIAL_RELEASE_SS => passed: passed=119,notpassed=0 (0.61 min)