Add bitly url shortening

Add excludes lists for bitly shortener. Only shorten longer urls.

Make sure config values are set.
Add goodbye plugin
Update readme. Add more information on contributing.

Update git ignore
Fix help command with unknown commands
Reconnect if connection lost
Seen command implemented. Tracks when users are active in the channel.

Goodbye Plugin improvements.
Fix readme

Remove inaccurate comment

Remove long goodbyes, and some of the others
Fix seen reply if bot hasn't seen the user.

Move Users class to seen plugin.

Fix !seen case sensitivity. Update users command doc string
Merge branch 'seen'

Smashed some commits, and cleaned some stuff up. Many fixes revised.

* seen:
  Fix seen reply if bot hasn't seen the user.
  Fix readme
  Seen command implemented. Tracks when users are active in the channel.
  Reconnect if connection lost
  Fix help command with unknown commands
  Update readme. Add more information on contributing.
  Add goodbye plugin
  Add bitly url shortening

Conflicts:
	README.mkd
	goodbye.txt
	hamper/plugins/bitly.py
	hamper/plugins/seen.py