Add a selected line sorter to the sandbox.

When I wrote this, I originally wrote it inside the Configuration project in order to test that it was working. Once I got it up to snuff I just kind of copied&pasted it into the github project. Since I don't actually know how to build and install from the source tree (I only install it from the Chrome store), I haven't actually tested this. So please give it a thorough stomping and make sure it works, who knows I might have made a copy&paste error or I might have put something in the wrong place.

Let me know if there's anything you don't like about this or anything that needs fixing.

Thanks!