TestingParty08: Cookie Domain

The generated cookie_domain in bootstrap.inc, conf_init() is not yet properly tested. This adds some tests for them in bootstrap.test.

Two notes:

• I had to resort to $GLOBALS['cookie_domain'] instead of global $cookie_domain due to some unexpected behaviour.
• There is a bug with the commented domains:
  

        // 'www2.drupal.org'        => '.drupal.org',
        // 'app.testing.drupal.org' => '.testing.drupal.org',
        // 'dev.drupal.co.uk'       => '.drupal.co.uk',
        // 'app.dev.drupal.co.uk'   => '.dev.drupal.co.uk',
  

  but i will open a separate issue once this test is added. Can we leave them in the patch here in the meantime?

Hopefully it is ok to put it under "Testing Party 08"...