Use correct OpenSSL thread safety macros on OS X (closes #209) Create an Autoconf test to determine if pthread_t is a pointer or scalar type, and use the appropriate CRYPTO_THREADID_set macro based on the result.

functor Make(M : sig
                 type t
                 val toString : t -> string
                 val fromString : string -> option t
             end) : sig
    val main : unit -> transaction page
end