The patch defines implementation of swift connection manager for
swift driver. It allows to receive swift connections and
update them if user token is going to expire soon.
Connection manager for single tenant store uses swift service
user credentials to receive new token.
Connection manager for multi-tenant store uses trusts to
receive new token and initialize a connection.
Please note that this is first part of bp implementation that
defines framework and helpers for re-authentication.
Implementation of keystoneclient initialization and enabling of
re-authentication for swift store available in next patch.
Implements bp prevention-of-401-in-swift-driver
Change-Id: I61b0fcfe284bdfbf4c0558178318c69617ec6127
142cf34c2f