message: Added default constructor for {Vector,}GridFunctionCoefficient
diff: @@ -167,6 +167,7 @@ private:
  int Component;
  public:
  + GridFunctionCoefficient() : GridF(NULL), Component(1) { }
  /** Construct GridFunctionCoefficient from a given GridFunction, and
  optionally specify a component to use if it is a vector GridFunction. */
  GridFunctionCoefficient (GridFunction *gf, int comp = 1)
  @@ -399,6 +400,7 @@ protected:
  GridFunction *GridFunc;
  public:
  + VectorGridFunctionCoefficient() : VectorCoefficient(0), GridFunc(NULL) { }
  VectorGridFunctionCoefficient(GridFunction *gf);
  void SetGridFunction(GridFunction *gf);
  