Attendee table

This branch incorporates the CSV field handling into the attendee table display, which lets us use a single filter/update form for the entire page. I also did some moving around / consolidating of content to allow maximum horizontal space for management (in particular attendee management.) A couple things that could be improved before or after this is merged:

1. make scrolling on attendee page horizontal only.
2. Add display of current management page title to masthead so people don't have to just key off the nav.
Wait, actually, my thought was to make the `render` method a generator (with `yield`, I guess?) and let the view handle if it wanted a streaming response. Either works though...