pass the simulation timer object instead of the time step size

models may need a more detailed picture of where they are in the
simulation. Note that since the timer objects are available at every
call site, this is also not a very deep change.

opm/autodiff/SimulatorBase_impl.hpp

@@ -207,7 +207,7 @@ namespace Opm
             }
             else {
                 // solve for complete report step
-                solver->step(timer.currentStepLength(), state, well_state);
+                solver->step(timer, state, well_state);
 
                 if( terminal_output_ )
                 {