allow coccinelle to compile w ocaml 4.00.0 and 4.01.0

coccinelle doesn't compile with pcre newer than 7.1.1 with ocaml 4.00.0 and
4.01.0, so I am fixing the version of pcre needed by coccinelle to 7.1.1
since not everybody is working with a bleeding edge 4.02.0 ocaml compiler