Cleans up interface (it's now a command line option) and renames project to "sqlcache" in the all-one-word style. Still has issues to do with concurrency, retrying transactions, and foreign function calls that either rely on state or have side effects.

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