Allow users to auth trello identities
Add incoming email processing

- Also adds delayed_job / delayed_job web
Authorize flow for getting a comment added
Worker task for heroku
Allow sending SMTP_EMAIL optionally
Messaging for reply comments
Sign in/out links for sanity
Send emails via delayed job
Send people individual emails about cards

- Don't send someone an email about an action they took
Make sure people that join are org members
TrelloIdentity is unique by uid
Make sure
Ignore emails sent to the default to address

- For legacy email replies
Associate trello account with the current user

- Weirdo edgecase hack!
Dummy rake task for delayed_job
Merge pull request #1 from a-warner/incoming_emails

Handle incoming emails