Monkey patch 'django.utils.translation'

Modify Django's translation library, such that the gettext family of
functions return an empty string when attempting to translate a
falsey value. This overrides the default behavior [0]:
> It is convention with GNU gettext to include meta-data as the
> translation for the empty string.

This patch provides a holistic solution to replace the current piecemeal
approach [1][2].

Affected Methods:
    - gettext
    - gettext_lazy
    - pgettext
    - pgettext_lazy
    - ugettext
    - ugettext_lazy

[0] https://docs.python.org/2.7/library/gettext.html#the-gnutranslations-class
[1] bad803e451ce63b4693ecf52b66cedfce5b43160
[2] https://github.com/edx/edx-platform/pull/4653
This is really pretty nice. I like all the docstrings.

If (as I muse about above) there is some mechanism for saying, "oops, just kidding, don't really do this because we're in the test harness) then you could write a unit test to confirm behaviour before and after patching. 

Even without it though, you could add a small test for post-patching that just confirms that ugettext takes '' and returns '' - this would be valuable as a way to be sure the monkey patch system is in place and working, and to document in one more way that this is intentional behaviour, and what the intentional behavior is.