[project @ 2001-08-20 16:17:17 by simonmar]

- be more informative about primitive types: they are identified as
  such, and a declaration is printed out as if the thing was an
  abstract data type (this at least tells you what the arity of the
  tycon is).

- print 'infix 4 elem' as 'infix 4 `elem`'.