Upload fallback.json instead of building wrappers.

Also report the location of the fallback.json to the controller,
instead of the wrapper location.

We still set ourselves up to build wrappers, which we'll only do
on demand from the controller.
Configure locales to remove log noise.
Send access data to controller.
Generate a randomish-looking cert.

This is the lantern_aws part of #1284.  I'm mixing this with the
issue1265 branch to save manual testing cycles.
Build and upload wrappers from least busy fallback.

Least busy fallback is determined by memory usage %.  All this is
done on prompt from the controller and the controller is informed
when we're done.  I think this concludes the lantern_aws part of
Merge branch 'issue1265' of github.com:getlantern/lantern_aws into issue1265

Conflicts:
	salt/fallback_proxy/init.sls
	salt/fallback_proxy/report_completion.py
Make download URLs a bit prettier.
Fix salt command format.
Use absolute paths for bash commands.

This broke when we changed the cloudmaster.py script to run as root,
which apparently doesn't have /usr/local/bin in its path.
Make new fallbacks default to new style.

Also, autogenerate auth token if not provided.
Merge pull request #18 from getlantern/issue1265

Issue1265