removed debug output
Merge branch 'master' of https://github.com/FAU-Inf2/fly-gdx
removed unnecessary entries form uiskin.atlas to reduce loading time
used default stlye for buttons to reduce amount of styles and the dependencies to UI-class
removed debug output, removed style references, loading of skin is reduced by 50% (1000ms -> 500ms on S2)
Merge branch 'master' of https://github.com/FAU-Inf2/fly-gdx
Merge branch 'master' of https://github.com/FAU-Inf2/fly-gdx