[ticket/13297] Add unicode modifier to url/email regular expression patterns

Besides, some functions calls getting replaced with their utf8 forms to allow
extensions introducing international domain names and email addresses.

<a href="https://tracker.phpbb.com/browse/PHPBB3-13297">PHPBB3-13297</a>.
Put that into the setUp() method:

```php 
	protected function setUp()
	{
		parent::setUp();

		global $config, $user, $request;
		$user = new phpbb_mock_user();
		$request = new phpbb_mock_request();
	}
```