Add support for default template parameters that contain scope and typedef.

namespace edm {
struct refhelper {
  template <typename what>
  struct ValueTrait {
    typedef typename what::value_type value;
  };
};

template <typename what,
	  typename trait = typename refhelper::ValueTrait<what>::value >
class Ref {
public:
  trait fValue;
};
}

#ifdef __ROOTCLING__
#pragma link C++ class edm::Ref<vector<Double32_t> >+;
#endif