Chat window panes (messages, users, typing) could use some sane minimums

I'm thinking the following:
- User list: 2ems (allows for the title and one line of users).  Could go for 3ems.
- Messages: 10ems? No idea on this one.  Would need to match the editor's minimum as well.
- Editor: 10ems as well?
- Typing window: 3ems?  Could go for 2 but that might be a little constricting.  Could go larger as well I suppose.
