Get and show the list of conversations

lib/utils/intl_utils.dart

@@ -5,7 +5,15 @@
 /// Translate a string
 ///
 /// Translate a given [string] into the current language, if available
-String tr(String string) {
+///
+/// Then apply the list of [args] to the string, each argument name is
+/// surrounded by '%'
+String tr(String string, {Map<String, String> args}) {
   //TODO : create translation system
+
+  //Apply arguments
+  if(args != null)
+    args.forEach((key, value) => string = string.replaceAll("%$key%", value));
+
   return string;
-}
+}

lib/utils/ui_utils.dart

@@ -18,7 +18,7 @@ Widget buildLoadingPage() {
 }
 
 /// Build and return an error card
-Widget buildErrorCard(String message) {
+Widget buildErrorCard(String message, {List<Widget> actions}) {
   return Card(
     elevation: 2.0,
     color: Colors.red,
@@ -39,6 +39,9 @@ Widget buildErrorCard(String message) {
               style: TextStyle(color: Colors.white),
               maxLines: null,
             ),
+          ),
+          Row(
+            children: actions == null ? <Widget>[] : actions,
           )
         ],
       ),