Fix multi-steady state test
Never take the abs of convergence values.
Add a DOLFIN_EPS to the time loop

This avoids pseudo-randome behaviour due to roundoff errors.
Remove current_time from the Problem classes
Introduce a MultiSteadyShallowWaterProblem.
Check that start time is < than finish time
Move all functional computation in the integrator
Remove Hessian computation, as not supported by da
Use names to refer to functions in the integrator
Remove the pseudo time loop from the integrator
Remove unused variables from sw solver
Add 1st order integration for MultiSteadySWProblem
Remove 0th order functional integration