Add influences by well perforations to matrix.

This is only done upon request and uses the auxiliary module approach
provided by ewoms.

In the case of adding the influences we do not execute applyWellModelScaleAdd
or applyWellModel in the operator

opm/autodiff/StandardWell.hpp

@@ -157,6 +157,7 @@ namespace Opm
 
         virtual void calculateExplicitQuantities(const Simulator& ebosSimulator,
                                                  const WellState& well_state); // should be const?
+        virtual void  addWellContributions(Mat& mat) const;
     protected:
 
         // protected functions from the Base class