Listing of available qualities

I thought it would be nice to see which qualities a stream supports without having to make it fail on purpose just to read the error-message of livestreamer. Selecting a stream via the twitch-browser now puts this information in the output-box.

I was tempted to have the browser pre-choose a quality or to convert the textfield into a dropdown-box with the available settings, but this is something which should probably be discussed first. Do you have any plans of letting the user choose a preferred quality or something like that? Maybe a ranked List of qualities from which the browser could then choose once it determined which ones are available?