Test more combinations of other effects together with sliding popups.
The problem does not only exist for scale in but for pretty much any
effect that the ordering in which the effects get loaded makes the test
pass or fail.
Some effects require OpenGL, as build.kde.org does not support OpenGL
compositing (yet), the tests only do the OpenGL cases if an OpenGL
compositor could be created.
CCBUG: 336866
The test case loads the sliding popups effect and the scale in effect
which also operates on added windows. As the test case shows depending
on the sequence how the effects are loaded, the window gets animated by
both effects (wrong) oor only sliding popups.
CCBUG: 336866
