Added default language pack (en-gb)

catalog/extension/recurring/pp_express.php

@@ -0,0 +1,11 @@
+<?php
+// Text
+$_['text_title']          = 'PayPal Express Checkout';
+$_['text_canceled']       = 'Success: You have succesfully caneled this payment!';
+
+// Button
+$_['button_cancel']       = 'Cancel Recurring Payment';
+
+// Error
+$_['error_not_cancelled'] = 'Error: %s';
+$_['error_not_found']     = 'Could not cancel recurring profile';