http://127.0.0.1:8000/xmlhttprequest/resources/basic-auth/basic-auth.py?uid=login3 - didReceiveAuthenticationChallenge - Simulating cancelled authentication sheet
http://badname:passpw@127.0.0.1:8000/xmlhttprequest/resources/basic-auth/basic-auth.py?uid=login4 - didReceiveAuthenticationChallenge - Simulating cancelled authentication sheet
Test for bug 13075: XMLHttpRequest with failed authentication should set status to 401.

Sync, no credentials: OK
Sync, incorrect credentials: OK
Async, no credentials: OK
Async, incorrect credentials: OK