Provide controls for customizing width/height of foreground popup

[MeoMix]

It would be nice to allow users to set Streamus back to 640 * 480px manually.

[Bound3R]

+1 :+1: it would be a nice touch, now I use it in the office and when need to change every song is a giant window superimposed on the browser

-it is not as discreet as before