sync latest strutils to python-cinderclient

This commit syncs the latest strutils code into
python-cinderclient.  The motivation for this sync is to get
access to the mask_password function that was added with commit
cb5a804b .

The sync touches both the strutils.py and gettextutils.py files.
The detailed breakdown of the sync is as follows:

Current HEAD in OSLO:
-----------------------------------
commit 5fa2dae429a9e37dfd1a527eb3957cea57a3e8c4
Merge: 5fb12c2 0506d17
Author: Jenkins <jenkins@review.openstack.org>
Date:   Tue Jul 15 10:05:12 2014 +0000
Merge "cfgfilter has graduated, remove it"
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Changes to strutils.py (newest to oldest):
-----------------------------------
cb5a804b  Move `mask_password` to strutils
8a0f5678  Remove str() from LOG.* and exceptions
fd18c288  Fix safe_encode(): return bytes on Python 3
302c7c80  strutils: Allow safe_{encode,decode} to take bytes as input
bec3a5eb  Implements SI/IEC unit system conversion to bytes

Changest to gettextutils.py (newest to oldest):
-----------------------------------
3d90045d  Backport code for i18n to check lazy at runtime
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

Change-Id: Icc38bc97e47c8236ccb82283c246bf266bc62929
Related-Bug: 1341735
Merge "sync latest strutils to python-cinderclient"