Validate the matrix solver interface for suitability in using other solvers

[samhatchett]

People at the WDSA meeting expressed some interest in testing newer and/or parallelized matrix solvers - Armadillo, MUMPS, Lapack++, etc.

Would just like to evaluate some of these commonly used libraries and make sure that the interface to MatrixSolver will work for these. Could also include wrappers for using these other libraries as a compile-time option.