Synced jsonutils and its dependencies from oslo-incubator

The sync includes change that makes sure we get unicode-only dicts from
jsonutils no matter which json module implementation is selected.

The latest commit in oslo-incubator:
- 2e1214b74b5448825d3db26e1308a51b468d3d5c

Included commits:
* gettextutils.py:
  - de4adbc4: pep8: fixed multiple violations
  - 9912e5df: Add API for creating translation functions
  - 6cc96d05: Fix test_gettextutils on Python 3
  - fd33d1ea: Fix gettextutil.Message handling of deep copy failures
  - 047b2e4e: Change lazy translation to retain complete dict
  - 6d55e26a: Add support for translating log levels separately
* importutils.py:
  - 1173e469: Remove ValueError when accessing sys.modules
  - 885828af: Deleted duplicated method in cliutils.
* jsonutils.py:
  - 0d7296f6: Add kwargs to jsonutils.load(s) functions
  - 18f2bc1b: Enforce unicode json output for jsonutils.load[s]()
  - 9e5a3938: jsonutils.load() accepts file pointer, not string
* timeutils.py:
  - 250cd88c: Fixed a new pep8 error and a small typo

The sync adds new module: strutils.

Disabled pep8 import checks for gettextutils to avoid raising 'H302:
import only modules.'

Change-Id: Ic815ca3df94c33edec9104172048b2cd94b92e3f
Closes-Bug: 1314129
Merge "Synced jsonutils and its dependencies from oslo-incubator"