Add Event to api types

I could see both of them as query parameters, but I'm not sure that the best way to describe that for a consumer is part of a URL (unless it's opaque).  Clients of one part of the API shouldn't have to know how to generate URLs to another unless that URL is guaranteed forever.

----- Original Message -----
> > @@ -621,3 +613,58 @@ type ServerOpList struct {
> >  }
> >  
> >  func (*ServerOpList) IsAnAPIObject() {}
> > +
> > +// ObjectReference contains enough information to let you inspect or
> > modify the referred object.
> > +type ObjectReference struct {
> 
> I think it still makes sense to have this be more than just a URL--
> ResourceVersion and FieldPath (or equivalent) wouldn't show up in a URL. Or
> should they?
>