Allow sorting on *ALL* columns

[JesseWeinstein]

Rather than having explicit buttons that only allow sorting on a few columns -- can we just implement a general sortable-columns library, that allows for arbitrary sorting on all the columns? Specifically, I'd love to be able to sort on whether or not documents are available.

[madoleary]

This is a good idea. I think there's a tool in Rails that we could use to help with this. I'll look into it once I've gotten a couple of other things off my to-do list.