Allow saving system matrix/rhs vector for non-iterative solvers.
Allow setting a preconditioner derived from Hermes::Preconditioners::Precond when the AztecOO backend is used.
Typo correction.
Virtualizing PicardSolver::init_solving.
Making the iteration counter available also during the initialization phase (it==0) of PicardSolver.
Matrix solvers: Making some methods that certainly do not change their mother-object const.
Matrix solvers update:
 - moving add_vector repeated in derived classes to the base class Vector
 - adding set_vector
Matrix solvers: Enabling matrix addition in umfpack_solver
Matrix solvers: enabling set_precond(Precond*) in AztecOO solver.
Small fix.
Minor documentation corrections.
Fixing invalid variable name in Nox OG projection class.
ErrorCalculator::component_count getter.
Solvers update.