New front page format

I reconfigured the home page of this group -- copied quite shamelessly from the NYC Drupal group. I think this will help give an overall snapshot of the group, and puts the focus on the next event, instead of (just) the discussion.

The all posts tab replicates what used to be on the home page, in a table format. I could switch it to the usual teaser format if folks like that better, but I do kind of like being able to scan through more at a time, and seeing what the keywords are. Of course, if you're following this through email or RSS, it doesn't make any difference.

Feedback welcome!