Minor feature request

Hi,
First of all, thank you so much for this plugin. It has been a tremendous help to us on our member site.

We have one minor feature request. On the Manage Subscriptions page, would it be possible to make the columns sortable? I’ve already changed the pagination a little so that it displays all the users on one page (we have 300+ users, so that made it easier to modify lots of users at once). Being able to sort by Name, Role, or Subscription would be awesome since we could quickly see who wasn’t subscribed, if someone had a role that required a subscription but didn’t have it, etc. Thanks for considering!

Matt