Revision 15672

from Axel:
Change the signature of SavePrimitive from

  void SavePrimitive(ofstream &out, Option_t *option);
to
  void SavePrimitive(ostream &out, Option_t *option = "");

With this change one can do, eg
   myhist.SavePrimitive(std::cout);

WARNING: do rm -f tree/src/*.o