This commit adds the ability to follow and unfollow (remote)
accounts and to display a list of followers and followees for
a specified account.
Changes:
- Added a command to follow an account.
- Added a command to unfollow an account.
- When displaying an account you can optionally view the relationship
between that account and yourself.
- Added a command to view accounts that are following a specified
account.
- Added a command to view accounts that are followed by a specified
account.