Django 1.6 is out, move Pootle long earlier

Makes more sense to get up to 1.6 level sooner so we're not caught out again on
an older version.
Cleanups

Remove unused imports and added blank lines to improve readability.
Fix Mozilla extension after the move to Pootle goals

Goals are now handled natively by Pootle, so no more shuffling of files
around.

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