offline tweaks

small tweaks that make working on HQ without internet a bit more pleasant

also one small functional change in d1f6991
Would it make more sense to throw the exception here instead of returning ```None```?  That would avoid risking ```NoneType``` errors in locations like https://github.com/dimagi/commcare-hq/commit/9835258411cc0d6ac4bddf80f0d6dedf30bf5670#diff-d0fc75977164149f014841ec01e63286R66