The added test case simulates that a Compositor is started on X11
and shut down again. This should trigger the themeChanged signals
and the imagePath should return different elements.
REVIEW: 128572
we have a color in the Plasma theme "highlight" that is basically
an accent color used around.. but one of the uses is to use it as
a background, such as highlighted text. in that case we don't know
what color would be safe for contrasting on top of it for things
like the highlighted text color (plasma style used the background
color for that, which is incorrect)
REVIEW:127637
