title: is utmcsr cookie unnecessary when utmgclid is set?
body: <p>I'm using PHP-GA lib, which provides a PHP implemention of GA: <a href="http://code.google.com/p/php-ga/" rel="nofollow">http://code.google.com/p/php-ga/</a></p>
  
  <p>When a user comes to my website from an Adwords link, utmcsr (source) cookie is NOT set, and utmgclid (Google click ID) is set instead.</p>
  
  <p>PHP-GA does not allow me to send Campaign tracking data to GA if the utmcsr cookie is not set. So I wonder if it is ok when I just send the utmgclid and NO utmcsr? (yes, I need to modify PHP-GA lib for that). Is all Campaign tracking data (especially Source/Medium) still correct?</p>