First working JFace example

[Frank Benoit]

> > - tango.util.collection.mode.Set
> >   line 37 add:
> >   public Set!(T) duplicate();
> >   public alias duplicat dup;

hm, should be Seq instead of Set.

 - tango.util.collection.mode.Seq
   line 37 add:
   public Seq!(T) duplicate();
   public alias duplicate dup;