Added default language pack (en-gb)

catalog/extension/total/voucher.php

@@ -0,0 +1,14 @@
+<?php
+// Heading
+$_['heading_title'] = 'Use Gift Certificate';
+
+// Text
+$_['text_voucher']  = 'Gift Certificate (%s)';
+$_['text_success']  = 'Success: Your gift certificate discount has been applied!';
+
+// Entry
+$_['entry_voucher'] = 'Enter your gift certificate code here';
+
+// Error
+$_['error_voucher'] = 'Warning: Gift Certificate is either invalid or the balance has been used up!';
+$_['error_empty']   = 'Warning: Please enter a gift certificate code!';