Use the authorization data we get back from the server to "continue" the

Use the authorization data we get back from the server to "continue" the
authentication dialog.

Set cupsLastError() and cupsLastErrorString() values based on the HTTP
status (needed by the cupsGetFile/Fd and cupsPutFile/Fd APIs).

Look at cupsLastError() for auth failures since Kerberos will not trigger
the password callback.

Make sure that we don't stick the "authkey" info in the WWW-Authenticate
header when Kerberos is being used.

git-svn-id: svn+ssh://src.apple.com/svn/cups/cups.org/trunk@6712 7a7537e8-13f0-0310-91df-b6672ffda945