Add new mod tiers.

Currently it doesn't do any checks against the tier hierarchy.
Check mod tiers against the tier hierarchy.
Front end for kicking and IP banning.

There's still a load of server side stuff that needs to be done for IP banning.
Back end for IP banning.

Prevent banned users from entering chats and expire bans after 30 days.
Redirect banned users to the oubliette.
Fix a couple of typos in the above.
Don't ban people from the oubliette.
Lookup global moderatorships and set session group accordingly.
Create script for adding/removing global mods.
Make it possible to enter a reason for a ban.
Send chats for archiving early if they reach 500 lines.
Change mod tier names and add descriptions.
Always give action lists black text.
Add BBCode mode to logs.
Don't hide silence.
Send a message when a user is silenced/unsilenced.
Disable text input for users who are silenced.
Use $.inArray rather than Array.indexOf.

Array.indexOf breaks IE and possibly mobile browsers too.
Allow all mods to set the conversation topic.
Limit topics to 1500 characters.