fix wrong type name: string --> usage_msg

git-svn-id: http://caml.inria.fr/svn/ocaml/trunk@14578 f963ae5c-01c2-4b8c-9fe0-0dff7051ff02
remove broken link in doc comment

git-svn-id: http://caml.inria.fr/svn/ocaml/trunk@14579 f963ae5c-01c2-4b8c-9fe0-0dff7051ff02
test reference files are now exempt from all rules

git-svn-id: http://caml.inria.fr/svn/ocaml/trunk@14580 f963ae5c-01c2-4b8c-9fe0-0dff7051ff02
remove tests that depend on camlp4

git-svn-id: http://caml.inria.fr/svn/ocaml/trunk@14581 f963ae5c-01c2-4b8c-9fe0-0dff7051ff02