Clean up some stuff around editing user

Instead of linking to edit user in dashboard nav, this links to users#show, with a link to edit_user_path. And it adds a form to update the user's name, location, website, and about. I think those are safe things to update all the time. @wallawe let me know what you think about that.

It also lists the theme name for each of a current_user's subscriptions. We'll have to see what all we can add to make the account settings better.