User Info Login Shortcode

I needed a way to display login form on the front page of a WPMU network if a person wasn’t already logged in, and a bit of info about the user, a list of their sites, a link to create a new one, and a link to logout. I could have done it by hacking the theme’s templates, but that locks you into a specific theme. With the shortcode, any theme can display this, on any page (or post, but why would you do that? whatever. it’s your site…)