Transparent themes without composition

[David Nolden]

Ok now let's forget this whole past part of the discussion, and start new in a 
productive manner.

The feature freeze will start today, so in order to get at least something 
useful into KDE 4.3, I now propose this:
- The Theme section of the plasma configuration file contains an additional 
configuraton entry "frameBackgroundColor". If that entry is set, the 
background of floating parts of non-opaque themes will be filled with that 
color in non-composite mode, within the theme-defined mask.
This configuration entry is needed to distribute the color across all the 
different places where it may be used, like kwin, krunner, plasma panel, etc.

This is only the backend part though. The next step would be automatically 
setting that color according to the wallpaper.