PR#6425: fix generation of man pages, handling variant constructors and record fields

git-svn-id: http://caml.inria.fr/svn/ocaml/version/4.02@14901 f963ae5c-01c2-4b8c-9fe0-0dff7051ff02
Changes: PR#6425

git-svn-id: http://caml.inria.fr/svn/ocaml/version/4.02@14903 f963ae5c-01c2-4b8c-9fe0-0dff7051ff02