OCaml interface to r2

Interact with radare2, See the mli for documentation, example usage in utop:

require "radare2";;

let result = R2.with_command_j ~cmd:"/j chown" "/bin/ls";; val result : Yojson.Basic.json = List [Assoc

[("offset", `Int 4294987375); ("id:", `Int 0);
 ("data", `String "ywritesecuritychownfile_inheritdi")]]"