Merge branch 'stitch_mesh' of https://github.com/jwpeterson/libmesh

This branch optimizes SerialMesh::stitch_meshes.
Merge branch 'stitch_mesh' of https://github.com/jwpeterson/libmesh

John updated the branch to pass the tolerance down.
Merge branch 'master' of github.com:libMesh/libmesh

Merging master.
Merge branch 'master' of github.com:libMesh/libmesh
Merge branch 'master' of github.com:libMesh/libmesh
Added miscellaneous_ex9: Example that demonstrates a discontinuity on an internal mesh interface, which requires the sparsity pattern to be augmented.
Reduced Basis change: Removed singe_matrix_mode. The purpose of this mode was to provide a low-memory version, which re-assembled matrices rather than storing them. But it wasn't used and therefore wasn't well tested, and it complicated the code for little benefit. If this functionality is desired in the future, better to put it in a subclass.
Fixes for PetscInt!=int compatibility
Rb stuff needs a non-const reference to dof_indices.
Use accessor API for FEMContext.
Update solvers to use updated FEMContext API.
Need non-const versions of these accessors. I'm not convinced this
is the right way to go here, but rolling with it for now.
Updating reduced_basis to use new FEMContext API's.
Assert on the private data structures.
Update to use new FEMContext API. Also needed a
non-const Elem&.
Return a reference to the QBase instead of a pointer.
Now make everything protected/private. The library builds for me,
but the examples still need to be updated so likely make check
will fail at this point.
Updated adjoints_ex1 to use the new FEMContext API.
Update adjoint_ex2 for new FEMContext API.
Update adjoints_ex3 to use new FEMContext API.