Updates nova client to use the latest oslo files

This patchset updates modules based on the config file:
openstack-common.conf

Notes: Some corrections has been added to work with
new files.
  + utils.py: The method safe_decode from strutils.py
    was updated and it is now not necessary to check for
    decode string with py33.
  + base.py: base64 needs a 8-bit string for py33
  + test_shell.py: stdin.encoding is needed for strutils

Change-Id: Iebe474f1226f8b5faa7fb5722e65f41b80d1973c
Related to blueprint common-client-library-2
Closes-Bug: #1265473
Merge "Updates nova client to use the latest oslo files"