split modules and fix Ev

src/ev.ml

@@ -0,0 +1,12 @@
+type type' = Jv.t
+
+module Event = struct
+  (*type for simple Event *)
+  type t = type'
+end
+
+module Mouse = struct
+  type t = type'
+
+  let latlng e = Latlng.of_jv_t @@ Jv.get e "latlng"
+end