MueLu: Adding PL option to always keep proc 0

Option (default=true) to always keep proc 0.  This gets around some limitations in MueLu's timer and statistics output.
Ifpack2: disable overlap if only on one proc

In AdditiveSchwarz, it doesn't make any sense to overlap on one processor.  This was partially
enabled in the Ifpack2::AdditiveSchwarz class, but was missing in the setParameters method.
This change is necessary to be able to use AS as a smoother in a multigrid method, where a coarse
level problem may be created on a single processor.
MueLu: command line toggle between gmres and cg
Ifpack2: making AdditiveSchwarz a little clearer

Adding type of subdomain reordering to AdditiveSchwarz description.
Making use of RCM explicit in AdditiveSchwarz.  This doesn't change the behavior, but previously this class relied on the fact that the default in Zoltan2 is
RCM.
Changed "schwarz: reordering type" to "schwarz: use reordering".  This makes sense because the reordering type is actually a Zoltan2 parameter.  Ifpack2 only
cares that reordering occurs -- it's up to the caller to make sure the Zoltan2 params are set correctly.
MueLu: adding example of ILUT with overlap
MueLu: updating repartition test #4.

Because of new option to keep data on proc 0.

Build/Test Cases Summary
Enabled Packages: Ifpack2, MueLu
Disabled Packages: MOOCHO
Enabled all Forward Packages
0) MPI_DEBUG => passed: passed=22,notpassed=0 (1.14 min)
1) SERIAL_RELEASE => passed: passed=18,notpassed=0 (0.75 min)
2) MPI_SS_DEBUG => passed: passed=106,notpassed=0 (2.07 min)
Other local commits for this build/test group: 7a11ef4, 7d7ad14, 097a427, ab8881a, 65bba21
Update tpls used by installation testing
Zoltan2 taskMapper fixing the run time error
Merge branch 'master' of software.sandia.gov:/space/git/Trilinos
Zoltan2: Task mapping - coordinate shift pre-processing function is added. If function is provided machine dimensions, it will shift the coordinates so that the biggest gap comes to wraparound.
Zoltan2:pqJaggedTest - added another option where the input files is readed from separate files by each rank concurrently.
KokkosCore: change ViewInitialize to call placement new)
Stokhos:  Ported KokkosArray SymmetricDiagonal and FlatCRS kernels.

I finally got around to moving the KokkosArray SymmetricDiagonal and
FlatCRS kernels into Stokhos, primarily so I can rerun them for the IJCM
paper.  I also got rid of the unit tests and performance tests that used
the original KokkosArray kernels.
MueLu: special treatment for xml sublists named "ParameterList"

In many situations, we want to pass the parameters from the xml file to
a third party application. For instance, we may want to pass a list of
parameters to a partitioner, or to a smoother. There was no general
mechanism in place to do that. Now, for factories which follow the new
standard of validated parameter lists, we reserve a sublist with name
"ParameterList" to be passed to applications.
MueLu: added control of Zoltan2 parameters from xml file

Now, user just needs to provide a <ParameterList name="ParameterList">
to specify Zoltan2 settings. I have set up some defaults too.
MueLu: removed an old internal implementation of Gauss-Seidel