Turn more sig/str items into records. Patch from Leo White.

git-svn-id: http://caml.inria.fr/svn/ocaml/trunk@14597 f963ae5c-01c2-4b8c-9fe0-0dff7051ff02
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git-svn-id: http://caml.inria.fr/svn/ocaml/trunk@14598 f963ae5c-01c2-4b8c-9fe0-0dff7051ff02
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git-svn-id: http://caml.inria.fr/svn/ocaml/trunk@14599 f963ae5c-01c2-4b8c-9fe0-0dff7051ff02
Support for the let%foo syntax as structure item.

git-svn-id: http://caml.inria.fr/svn/ocaml/trunk@14600 f963ae5c-01c2-4b8c-9fe0-0dff7051ff02
Doc.

git-svn-id: http://caml.inria.fr/svn/ocaml/trunk@14601 f963ae5c-01c2-4b8c-9fe0-0dff7051ff02