Update tweet listener to listen to...
- All specified keywords
- All tweets and replies from the 5000 most recent tweeters in the system

Also update listener to automatically attach replies to visions
Differentiate between user and app tweet
- Add an app_tweet field (the tweet field now refers to the user-tweet)
- Update the admin to show tweets that are assigned as either a user tweet or an app tweet as visions
Reply to the app_tweet iff no user tweet is set
Fix listener issues
- Only select distinct users to follow
- Make sure that replies made through the app are not duplicates
Merge branch 'master' into homepage-refresh

Conflicts:
	src/visionlouisville/models.py
	src/visionlouisville/tasks.py
Merge pull request #4 from openplans/homepage-refresh

Homepage refresh
Delete old migration left over from the merge
Update README.md
Merge branch 'master' into with-tweeted-dt

Conflicts:
	src/visionlouisville/models.py
Store tweeted_at time on visions and replies
Order tweets and replies by the tweeted datetime
Update templates to display tweeted_at insetead of created_at datetime