- Work on Language Handler and extension.

- Added an URL extension which allows routes and URLs.
- Fixed some bug within ClassTemplate

src/Extension/LanguageHandler.php

@@ -0,0 +1,8 @@
+<?php
+
+namespace Picea\Extension;
+
+interface LanguageHandler 
+{    
+    public function languageFromKey(string $key, array $variables = []) : string;   
+}