Add new headers to language stuff

lib/editor/lang/en.php

@@ -1,3 +1,15 @@
+<?php
+    include("../../../config.php");
+    $lastmodified = filemtime("en.php");
+    $lifetime = 1800;
+ 
+    header("Content-type: application/x-javascript");  // Correct MIME type
+    header("Last-Modified: " . gmdate("D, d M Y H:i:s", lastmodified) . " GMT");
+    header("Expires: " . gmdate("D, d M Y H:i:s", time() + $lifetime) . " GMT");
+    header("Cache-control: max_age = $lifetime");
+    header("Pragma: ");
+ 
+?>
 // I18N constants
 
 // LANG: "en", ENCODING: UTF-8 | ISO-8859-1
@@ -11,10 +23,6 @@
 //   2. PLEASE TRY TO USE UTF-8 FOR ENCODING;
 //      (if this is not possible, please include a comment
 //       that states what encoding is necessary.)
-<?php
-	include("../../../config.php");
-	
-?>
 HTMLArea.I18N = {
 
 	// the following should be the filename without .js extension