#1055 Grouping and sorting of text messages (PR #198)

* Initial grouping of messages_en.yml (thanks to input by @Twonox)
* Change MessageFileVerifier to only do verification - no writing
* Create classes for sorting and grouping messages as per the messages_en file

src/main/java/fr/xephi/authme/message/MessageKey.java

@@ -252,4 +252,9 @@ public enum MessageKey {
     public String[] getTags() {
         return tags;
     }
+
+    @Override
+    public String toString() {
+        return key;
+    }
 }