Port fixes for JCLOUDS-178 to SwiftAuth and Keystone v1.1 (JCLOUDS-589)

Reauthenticate on HTTP 401. Orig commit: 578a77d6313ce0945f8d29e82103e09787622c58

Closes #589.
The reason retries are limited is that sometimes jclouds would attempt to retry "access denied" operations, and this is the best way to detect such a case (so far).