Remove references to FLAGS from volume/manager.py

Note that we still must import flags.py because volume_topic is defined
in the list global_opts in flags.py.

Fixes bug #1153551

Change-Id: I3d37bde4ba895c110390cea92385344ff94cb7d1
CoraidDriver: retrive volume info (improvement)

Some portions of code into this method are useless since
the REST API on Coraid side has been improved.

Fixes bug #1157242

Change-Id: Ie37b5b76710e77acb2acf627c9688e4f931e686c
Merge "CoraidDriver: retrive volume info (improvement)"
Merge "Remove references to FLAGS from volume/manager.py"