Synced jsonutils and its dependencies from oslo-incubator

The sync includes change that drastically enhances performance on Python
2.6 with fresh simplejson library installed.

The latest commit in oslo-incubator:
- 2e1214b74b5448825d3db26e1308a51b468d3d5c

Included commits:
* gettextutils.py:
  - de4adbc pep8: fixed multiple violations
  - 9912e5d Add API for creating translation functions
  - 6cc96d0 Fix test_gettextutils on Python 3
  - fd33d1e Fix gettextutil.Message handling of deep copy failures
  - 047b2e4 Change lazy translation to retain complete dict
* importutils.py:
  - 1173e46 Remove ValueError when accessing sys.modules
  - 885828a Deleted duplicated method in cliutils.
* jsonutils.py:
  - 0d7296f Add kwargs to jsonutils.load(s) functions
  - 18f2bc1 Enforce unicode json output for jsonutils.load[s]()
  - 9e5a393 jsonutils.load() accepts file pointer, not string
  - a6b2aec On Python <= 2.6, use simplejson if available
  - e3a1d9c Use six.moves.xmlrpc_client instead of xmlrpclib
* strutils.py:
  - 8a0f567 Remove str() from LOG.* and exceptions
  - fd18c28 Fix safe_encode(): return bytes on Python 3
  - 302c7c8 strutils: Allow safe_{encode,decode} to take bytes as input
  - bec3a5e Implements SI/IEC unit system conversion to bytes
  - e53fe85 strutils bool_from_string, allow specified default
* timeutils.py:
  - 250cd88 Fixed a new pep8 error and a small typo

Change-Id: Ib3dc0b713ed90396919feba018772243b3b9c90f
Closes-Bug: 1314129
Merge "Synced jsonutils and its dependencies from oslo-incubator"