converters/ocaml-jsonm: update the port to version 1.0.1 and

• Chase HTTP/1.1 301 redirection when fetching the distfile
• Update license (ISCL), assume maintainership of the port
• Use provided build scripts instead of performing it manually
• Convert to static pkg-plist, 16 lines don't warrant dynamic

devel/ocaml-uutf: (required) update the port to version 1.0.2
and make changes similar to the above;

devel/ocaml-topkg: call `do-build' recipe in ${BUILD_WRKSRC}.