Introducing NNC output

* Compute NNC by face2cell information from a grid
* Pass NNC information to EclipseWriter
* Made NNC respect ECLIPSE input data
* nncStructure() is now exportNncStructure()

opm/autodiff/SimulatorBase_impl.hpp

@@ -110,7 +110,7 @@ namespace Opm
         }
 
         // init output writer
-        output_writer_.writeInit( timer );
+        output_writer_.writeInit( timer, geo_.nnc() );
 
         std::string restorefilename = param_.getDefault("restorefile", std::string("") );
         if( ! restorefilename.empty() )