Now solvers return solver performance information for all components
with backward compatibility provided by the "max" function which created
the scalar solverPerformance from the maximum component residuals from
the SolverPerformance<Type>.

The residuals functionObject has been upgraded to support
SolverPerformance<Type> so that now the initial residuals for all
(valid) components are tabulated, e.g. for the cavity tutorial case the
residuals for p, Ux and Uy are listed vs time.

Currently the residualControl option of pimpleControl and simpleControl
is supported in backward compatibility mode (only the maximum component
residual is considered) but in the future this will be upgraded to
support convergence control for the components individually.

This development started from patches provided by Bruno Santos, See
http://www.openfoam.org/mantisbt/view.php?id=1824