new feature: handout a wrapped dune-function basis

dune/fufem/functionspacebases/dunefunctionsbasis.hh

@@ -86,6 +86,12 @@ public:
 #endif
   }
 
+/** \brief Handout a wrapped dune-function basis
+ */
+const DFBasis& wrappedBasis() const{
+    return dfBasis_;
+}
+
 protected:
 
   // The dune-functions basis we are wrapping