add libtool_version.ml

src/api.ml

@@ -8,8 +8,6 @@
      - payto_uri
      - uri *)
 
-let protocol_version = "31:0:0"
-
 open Time
 open Crypto
 open Signatures
@@ -206,7 +204,7 @@ end
 
 module ExchangeVersionResponse = struct
   type t = {
-    version: string;
+    version: Libtool_version.t;
     (* todo jsont const string
        `name: "taler-exchange"` *)
     name: string;
@@ -241,7 +239,7 @@ module ExchangeVersionResponse = struct
     let currency_specification v = v.currency_specification in
     let aml_spa_dialect v = v.aml_spa_dialect in
     map ~kind:"ExchangeVersionResponse" make
-    |> mem "version" Jsont.string ~enc:version
+    |> mem "version" Libtool_version.jsont ~enc:version
     |> mem "name" Jsont.string ~enc:name
     |> mem "implementation" (Jsont.option Jsont.string) ~enc:implementation
     |> mem "currency" Jsont.string ~enc:currency
@@ -273,7 +271,7 @@ let currency_specification =
 let config =
   ExchangeVersionResponse.
     {
-      version= protocol_version;
+      version= Libtool_version.mte_protocol_version;
       name= "taler-exchange";
       currency= Config.currency;
       currency_specification;
@@ -1230,7 +1228,7 @@ end
 module ExtensionManifest = struct
   type t = {
     critical: bool;
-    version: string;
+    version: Libtool_version.t;
     config: Jsont.json option;
   }
 
@@ -1241,7 +1239,7 @@ module ExtensionManifest = struct
     let config v = v.config in
     map ~kind:"ExtensionManifest" make
     |> mem "critical" Jsont.bool ~enc:critical
-    |> mem "version" Jsont.string ~enc:version
+    |> mem "version" Libtool_version.jsont ~enc:version
     |> opt_mem "config" (Jsont.any ()) ~enc:config
     |> finish
 end
@@ -1250,7 +1248,7 @@ module ExchangeKeysResponse = struct
   module String_map = Map.Make (String)
 
   type t = {
-    version: string;
+    version: Libtool_version.t;
     base_url: string;
     currency: string;
     shopping_url: string option;
@@ -1366,7 +1364,7 @@ module ExchangeKeysResponse = struct
     let extensions v = v.extensions in
     let extensions_sig v = v.extensions_sig in
     map ~kind:"ExchangeKeysResponse" make
-    |> mem "version" Jsont.string ~enc:version
+    |> mem "version" Libtool_version.jsont ~enc:version
     |> mem "base_url" Jsont.string ~enc:base_url
     |> mem "currency" Jsont.string ~enc:currency
     |> opt_mem "shopping_url" Jsont.string ~enc:shopping_url