Add vim modelines to all files.

Signed-off-by: Edward Z. Yang <edwardzyang@thewritingpot.com>

library/HTMLPurifier/Language/classes/en-x-test.php

@@ -9,3 +9,4 @@ class HTMLPurifier_Language_en_x_test extends HTMLPurifier_Language
 
 }
 
+// vim: et sw=4 sts=4

library/HTMLPurifier/Language/messages/en-x-test.php

@@ -8,3 +8,4 @@ $messages = array(
     'HTMLPurifier' => 'HTML Purifier X'
 );
 
+// vim: et sw=4 sts=4

library/HTMLPurifier/Language/messages/en-x-testmini.php

@@ -9,3 +9,4 @@ $messages = array(
     'HTMLPurifier' => 'HTML Purifier XNone'
 );
 
+// vim: et sw=4 sts=4

library/HTMLPurifier/Language/messages/en.php

@@ -58,3 +58,4 @@ $errorNames = array(
     E_NOTICE  => 'Notice'
 );
 
+// vim: et sw=4 sts=4