enable building flashlight servers

Right now only the infrastructure to build a new server type and to
install go is there.
remove leftovers from when fallbacks used to build wrappers
first shot at flashlight module

It doesn't register itself in Cloudflare yet.
Merge branch 'master' into flashlight
use upstart for managing flashlight service
flashlight servers register their domains on setup

You can call `register_domains.py unregister` to remove the records
thus created.  At the moment, this is not ever done automatically.
don't build flashlight; just download it from S3
refactor out proxy ufw rules
adapt upstart script to new calling scheme

Also refactor out the getiantem.org domain to a 'zone' jinja variable
to avoid duplication.
refactoring and changes to select launch profile per instance

This will allow us to deploy flashlight servers with a different
size and location than our lantern fallbacks.

Also allows enabling private networking where available.

The logic for finding out the local IP is centralized.

Some other cleanup.
Merge pull request #28 from getlantern/flashlight

Flashlight