RGridReader tweaks

Modules/LemmaCore/include/GridReader.h

 
             virtual void ReadASCIIGridFile( const std::string& name )=0;
 
-            virtual std::shared_ptr< Grid > GetGrid( )=0;
+            virtual std::shared_ptr< Grid > GetGrid( ) const =0;
 
             // ====================  ACCESS        =======================
 

Modules/LemmaCore/include/RectilinearGridReader.h

              * Accessor method for the underlying RectilinearGrid class constructed
              * from the input file.
              */
-            std::shared_ptr<Grid> GetGrid();
+            virtual std::shared_ptr<Grid> GetGrid() const ;
 
             // ====================  INQUIRY       =======================
 

Modules/LemmaCore/src/RectilinearGridReader.cpp

     //       Class:  RectilinearGridReader
     //      Method:  GetGrid
     //--------------------------------------------------------------------------------------
-    std::shared_ptr<Grid> RectilinearGridReader::GetGrid (  ) {
+    std::shared_ptr<Grid> RectilinearGridReader::GetGrid (  ) const {
         return std::static_pointer_cast<Grid> (rGrid);
+        //return rGrid;
     }		// -----  end of method RectilinearGridReader::GetGrid  -----