[Pkg-kde-extras] Bug#781376: Bug#781376: Bug#781376: oxygen-gtk3: Do not depend on libgtk-3-0

[Scott Kitterman]

The point of packages like this is to make gtk based applications look better when used in a Plasma environment. 

Consider the idea of an installation that includes no gtk applications to start with. In such an installation as this, the package has no immediate use, so not having a gtk depends does no harm and keeps gtk off a system where it's really not needed. 

Then later, when a gtk using application is installed, and gtk is pulled onto the system because of it, it will automatically look nice because the oxygen theme was already there. 

Scott K