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

Reauthenticate on HTTP 401. Orig commit: 578a77d6313ce0945f8d29e82103e09787622c58

Closes #589.
@andrewgaul Done.
@zack-shoylev There is already a test for this. test401ShouldRetry4Times().