PR#6274: allow doc comments on object types
(thanks to Thomas Refis)


git-svn-id: http://caml.inria.fr/svn/ocaml/trunk@14909 f963ae5c-01c2-4b8c-9fe0-0dff7051ff02
Fix ocamldoc test to follow new interface; add object type test


git-svn-id: http://caml.inria.fr/svn/ocaml/trunk@14910 f963ae5c-01c2-4b8c-9fe0-0dff7051ff02