a test for element renumbering #3198
RichardsMaterial substantially tidied up and derivatives are now
calculated wrt general variables rather than just porepressures

Also, some optimisation has been included with not calculating
SUPG things if no SUPG is used

Kernels have been updated to use these more general derivatives

RichardsSUPG now provdes a "trivial" function indicating
whether SUPG is trivial or not

RichardsVarNames now has a MooseEnum that describes what the
variables correspond to physically.  However, only the PPPP formulation
is actually coded in RichardsMaterial.

Sometime in the future I or someone else might be interested
in implementing the PSS material in full, and these changes will
make that far easier.  However, this changeset does NOT actually
implement this capability.  I have added a long essay to
issue #3241 why this is so.

Fixes #3241
JxW neighbor in Assembly class has to come from the surface (closes #3345)

When integrating over the face surface, transformed jacobian weights
have to come from the surface.  It was incorrectly implemented and JxW
came from the volume. This also fixes the memory leak introduced by
copying a JxW array into another MooseArray.
Issue #3346 Added getters for Warehouses in nl. Removed nl friends.
libMesh update.  Refs #000.
Merge pull request #3351 from WilkAndy/psss_3241

RichardsMaterial substantially tidied up and derivatives are now
Adding ability to specify a unique ID for a Dirac point.

This can be used to speed up the performance of DiracKernel::addPoint(p)
by avoiding the PointLocator step on subsequent additions of the same point.

Refs #2364.
Adding a test to demonstrate the Dirac point caching.

Refs #2364.
Adding an expect_err test that demonstrates the error handling when
you try to cache a point with a "unique" ID that's already taken.

Refs #2364.
Adding Dirac point reverse cache id lookup as requested by @WilkAndy

Refs #2364.
Update the CachingPointSource test to look up the current point's ID.

Also fixed BCs and renamed the output and gold files to avoid clashing
with an expect_err test in the same directory that used the same
filename.

Refs #2364.
Use DiracKernel caching and currentPointCachedID()
in RichardsBorehole and RichardsPolyLineSink.

Refs #2364.
Handle caching when Elem containing Point is not active.

The other two cases of interest,
* (active && !contains_point)
* (!active && !contains_point)

currently fall back to PointLocator searches, but I have
some ideas for how these could be optimized.  Still need
to add a test case for the refinement case.

Refs #2364.
Adding test of uniform refinement with Dirac point caching.

Refs #2364.
Adding test of adaptive refinement with Dirac point caching.

Refs #2364.
Optimizing PointLocator usage in DiracKernels.

Refs #2364.
Removing cache-disabling mesh adaptivity branches from Richards tests.

This also obviated the need for the mesh_adaptivity parameter itself,
so the patch also removes that from several input files.  @WilkAndy
may prefer to keep the parameter anyway, just let me know.

Refs #2364.
Handle the case where the Dirac point is not found on the Mesh.

Refs #2364.
Adding Dirac point caching test with moving mesh.

The Dirac points leave the domain (and hence become deactivated)
in this test.

Refs #2364.
Caching only Dirac point data for local elements

This seems to fix the moving-mesh-in-parallel case, but introduced
some new strangeness in the adaptivity tests.  It is working for the
moment but I don't think it's quite ready to merge yet.

Refs #2364.