Tweak .merlin
Tweak .merlin

* get rid of useless PRJ flag
* add lwt syntax extension flag

mor1/ocaml-cohttp,fdopen/ocaml-cohttp,mor1/ocaml-cohttp,fdopen/ocaml-cohttp,marklrh/ocaml-cohttp,dsheets/ocaml-cohttp,Drup/ocaml-cohttp,edwintorok/ocaml-cohttp,edwintorok/ocaml-cohttp,edwintorok/ocaml-cohttp,dsheets/ocaml-cohttp,fdopen/ocaml-cohttp,inhabitedtype/ocaml-cohttp,marklrh/ocaml-cohttp,inhabitedtype/ocaml-cohttp,Drup/ocaml-cohttp,dsheets/ocaml-cohttp,marklrh/ocaml-cohttp,inhabitedtype/ocaml-cohttp,Drup/ocaml-cohttp,mor1/ocaml-cohttp