Fix and gate on H302 (import only modules)

H302 is already part of the OpenStack style guide, and we only had a few
violations.  This fixes and gates on H302, so there is one less thing
for a reviewer to worry about.

gettext import line is ignored using hacking 0.7's import_exceptions
option.

Reason for import only modules 'The namespace management convention is
simple. The source of each identifier is indicated in a consistent way;
x.Obj says that object Obj is defined in module x.'
http://google-styleguide.googlecode.com/svn/trunk/pyguide.html

Change-Id: I53e8039f1dd2ebf8ab5fcf5a561feb3ca3363107
Merge "Fix and gate on H302 (import only modules)"