Lots of changeds to automatically create users the first time they hit the API to enable giving open downloaders invites getlantern/lantern#1680
Adding back in S3 links given inconsistent nature of blocking and in case github is blocked
more changes to strip out old invite logic with user-specific config files
Merge pull request #77 from getlantern/1680

Lots of tweaks to enable invites for open downloaders 1680