Sync gettextutils.py from oslo-incubator

This pulls in the latest gettextutils.py from oslo-incubator.
The primary reason for this sync is to get commit
3d90045d2d1ce1df89f75937f415e3982e111063 which backports a
change from the new i18n library to check lazy enablement
at runtime.  Adding this change makes it possible to remove
the global enablement of lazy translation through
gettextutils.install().  Instead we will use gettextutils.enable_lazy()
with explicit imports of _() in each file where _() is used.

The change to remove gettextutils.install() and to add the
explicit _() imports will come in a dependent patch.

Current HEAD in OSLO:
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Merge: 3d90045d2d1ce1df89f75937f415e3982e111063
Date: Mon, 07 Jul 2014 17:55:18 +0000
Merge "Backport code for i18n to check lazy at runtime"
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Additional changes being merged (newest to oldest):
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de4adbc4 - pep8: fixed multiple violations
9912e5df - Add API for creating translation functions
6cc96d05 - Fix test_gettextutils on Python 3
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related - blueprint: i18n-enablement
Change-Id: I4706b89b0b64c5816a1a022b6cd1dfa01b29b5dc
Merge "Sync gettextutils.py from oslo-incubator"