compile otherlibs/{dynlink,threads} in safe-string mode

git-svn-id: http://caml.inria.fr/svn/ocaml/branches/safe-string@14632 f963ae5c-01c2-4b8c-9fe0-0dff7051ff02
change deprecated function calls in test suite

git-svn-id: http://caml.inria.fr/svn/ocaml/branches/safe-string@14633 f963ae5c-01c2-4b8c-9fe0-0dff7051ff02
tie down loose ends and bootstrap

git-svn-id: http://caml.inria.fr/svn/ocaml/branches/safe-string@14634 f963ae5c-01c2-4b8c-9fe0-0dff7051ff02