mwimport.py: unused python import

Change-Id: If3b5bef75e6424354083a2af7ecc0c0631625182
pass pep8/pyflakes

Change-Id: I5aaec3b9931030e1394d6efe90686461816df446
Remove unused $wgTitle/$wgOut

Change-Id: I52acb8653180a96fbd79f207a50144a55f8cd53d
Migrate to JSON i18n

Procedure per https://www.mediawiki.org/wiki/Manual:GenerateJsonI18n.php
with shim.

Change-Id: I0fe454249f38f3f01a3ce3a041fccf6f80d15bf8
Remove unneeded and/or duplicate globals

Change-Id: I36879792865c1c272a83163a3c84cb5ba59781da