Override the validation url

[erozqba]

Hello,
Using phpCAS is possible to override the validation URL but not with XavRsl/Cas.
Example:
https://github.com/Jasig/phpCAS/blob/master/docs/examples/example_custom_urls.php#L39

// Override the validation url for any (ST and PT) CAS 2.0 validation
phpCAS::setServerProxyValidateURL('https://cas.example.org:1443/proxyValidate');
// Override the validation url for any CAS 1.0 validation
//phpCAS::setServerServiceValidateURL('https://cas.example.org:1443/serviceValidate');
//Override the validation url for any SAML11 validation
//phpCAS::setServerSamlValidateURL('https://cas.example.org:1443/samlValidate');

I really need this option to retrieve custom attributes for the logged user, so I will submit a patch for this.