Add-in some re-auth logic when using os_cache

When using os_cache for the auth_token, if username and password
are available when a token fails to validate/authenticate, attempt
a reauth behind the scenes.

The helper object for stashing the auth_token doesn't handle flushing
the cache.  This is valid behavior because the result would be the
same as if a bad username/password were issued (401 Unauthorized).

Fixes-bug: 1214658
Change-Id: I107fc999610bb7638cefcb5d195aeafdcd663ca6
Add shelve/unshelve/shelve-offload command

The "shelve" API, which powers off and snapshots a vm instance, has been
implemented by Nova-server side.
In addition, thare are two relational API "unshelve" and "shelveOffload".
This patch adds three commands for using these APIs.

Fixes bug #1231827

Change-Id: Ic2ad1bb537efb40a3155e9f3c7b63e09e82be7f1
Merge "Add shelve/unshelve/shelve-offload command"
Merge "Add-in some re-auth logic when using os_cache"