MueLu: switch to uncoupled aggregation in test

Grr, this test was using coupled aggregation.  This is fine, but you can't use the CoordinatesTransferFactory
with it.
MueLu: disabling ScalingTestParamList for Epetra.

This is only temporary, until the hang issues with Epetra are sorted out.
Along the way, I noticed a mistake in CMakeLists.txt, in which the the same test name,
"ScalingTestParamListEpetra", was being used 3 times in a row.  Only the last definition
was being used.  So I gave each one a unique name, but left them all commented out.
Finite element discretization for Helmholtz with PMLs in Galeri.
I changed some of the stuff in Utils to be compatible with complex.

Build/Test Cases Summary
Enabled Packages: Galeri, MueLu
0) MPI_DEBUG => passed: passed=5,notpassed=0 (1.26 min)
1) SERIAL_RELEASE => passed: passed=6,notpassed=0 (0.82 min)
2) MPI_DEBUG_SS => FAILED: passed=43,notpassed=1 => Not ready to push! (6.21 min)
WARNING: Forced the push!
MueLu: add missing information about stridedMaps to subblocks of blocked CrsOperator objects.
MueLu: add some debug output
MueLu: minor compile fix
MueLu: fix uninitialized variable.
cast enum to int for ==-comparison

This avoids hundreds of warning messages about comparisons between incompatible
enums.
Xpetra: Fixing EpetraCrsMatrix bugs.
Xpetra: ESFC bugfix.
Xpetra: Fixing typos
MueLu: Adding fast construction for Ptent.
Epetra: Someone changed something somewhere else.

And thus, I needed to change this to please valgrind.
Epetra: Fixes for restricted communicators.
Xpetra: Communicator reduction refactor/cleanup.

Making Tpetra & Epetra play similarly is hard.
MueLu: Ptent fixes and RebalanceAc cleanup.

ArrayRCPs are twisted beasts that come from the darkest places...
Xpetra: Removing debugging info
MueLu: Re-enabling Epetra scaling tests.

"We live on a placid island of ignorance in the midst of black seas of infinity, and it was not meant that we should voyage far."

- H.P Lovecraft, "The Call of Cthulhu"

Build/Test Cases Summary
Enabled Packages: Epetra, MueLu, Xpetra
Enabled all Forward Packages
0) MPI_DEBUG => passed: passed=778,notpassed=0 (32.70 min)
1) SERIAL_RELEASE => passed: passed=737,notpassed=0 (10.73 min)
Other local commits for this build/test group: 6f96eab, 3c7c676, 36b620f, 74fbfdd, cac03a7, 7b9077e, 1e7fda8, 172dde3, b4fdbbd
also find libXdmf.* when searching for XDMF libraries
MueLu: Adding a scaling test just for the construction of R.