[Xfburn] Adding padding option

[stealth]

I've added the padding option with no internals yet. I'm sure you guys
know more input methods than I do. So I'm wondering what you guys think is
the best way for the user to input how much padding they want. Just a
simple pop up box with input?, or should I move it to the bottom and have
them click a selection?. (This is under audio composition)


https://bugzilla.xfce.org/show_bug.cgi?id=8076



Thanks
-Stealthy