Refactoring of EffectFrame: EffectFrame becomes an interface just like EffectsHandler and EffectWindow and a concrete EffectFrameImpl in core.
Rendering of the EffectFrame is moved into the scene as Scene::EffectFrame with a concrete implementation in SceneXrender and SceneOpenGL.
A factory method for an EffectFrame is added to the EffectsHandler, which is used by the effects.
Next step: pass the EffectFrame through all effects, so that effects can transform, blur, invert whatever it.

svn path=/trunk/KDE/kdebase/workspace/; revision=1151271