Check return code when calling subprocess and throw better error
closes #2898
Test reading a Gmsh file with BCs

The test reads a Gmsh file with lower-dimensional elements
which specify BCs, and solves a Laplace problem on that mesh.

Refs #1402.
Restricing test
refs #2972
Merge pull request #2994 from permcody/restrict_test

Restricing test
Merge commit 'd581e017cf76be14b2f9123a314221c0571ed68e'
More operator spacing for #2951
Calculate gradient normal direction wrt PBCs.
Merge pull request #2992 from jwpeterson/gmsh_test

Test reading a Gmsh file with BCs (Requires libmesh update)
Fixing my bad typing - refs #2972
Merge commit '908e5e1e624f17b3fd3bc59b9780a4a5a6807dba'
make eigen executioners more modular #2983
fix gold files due to timing changes #2983
Merge commit '8f64b4878ab6ac9d4eca303b852ead36e350417a'
remove the exec_custom business #2983
Size stateful neighbor materials - refs #2972
Merge pull request #2984 from YaqiWang/eigen_modular_2983

Make eigen executioners more modular
Change the behavior of --mesh-only slightly.

When a filename is not provided, or when an Exodus file is requested,
we now write it using the "logical" dimension of the Mesh rather than
the spatial dimension (which is the default).  This helps us better
support visualizing 2D triangular meshes in peacock, since they will
now show the correct sidesets.

Interestingly, this did not require regolding any of the --mesh-only
MOOSE tests, since they were all already 3D.  But you can see the
issue if you open $MOOSE_DIR/test/tests/mesh/gmsh_bcs/plate_hole.msh
in peacock before and after the patch.

Refs #1568.
Update peacock for default name change (#2609)
Merge pull request #2993 from dschwen/feature_2965

Calculate gradient normal direction wrt PBCs.
Merge pull request #2989 from permcody/peacock_err_check_2898

Check return code when calling subprocess and throw better error