Add user gravatar after registration
Add more seeds
Add unblock friendship
Modify 'Add Friend' button depending on friendship status
Add tests for user unblock
Modify push updates to show 'You' for current_user
Clear push updates if user not authenticated
Change placeholder image on sign up page
Fix bug when changing profile avatar
Hide cancel membership button

TODO: soft user deletion on cancel membership:
- add deleted_at field
- mark user deleted
- don't allow login to deleted user
- user_page: no info, buttons, avatar
- don't delete friendships, statuses, albums, activities for now,
  just change avatar to default
- log out user on deletion and show flash message
Prohibit a user from adding oneself as friend
Add README
Update production action mailer settings