Add DofMap::local_variable_indices()
Added LinearSolver::init_names()
KSPSetOptionsPrefix calls PCSetOptionsPrefix

So we don't need to do so redundantly
Check for errors, simplify code
Command line option for solver names
Add names support to NewtonSolver
Optional name argument to FooSolver::init()
Support --solver_system_names
DiffSystem --solver_system_names works now
LinearImplicitSystem --solver_system_names works