add MessageKey method to CommandIssuer and misc stuff

sponge/src/main/java/co/aikar/commands/SpongeCommandIssuer.java

@@ -50,6 +50,11 @@ public class SpongeCommandIssuer implements CommandIssuer {
         return (T) this.source;
     }
 
+    @Override
+    public CommandManager getManager() {
+        return manager;
+    }
+
     @Override
     public void sendMessage(MessageType type, String message) {
         message = format(manager, type, message);