Similar to the Settings application, this adds a single Screensaver
application to launch all screensaver demos. This is to declutter the
taskbar menu a bit.
With everything now using GUI::FileIconProvider and therefore loading
icons embedded in the executable files, this information is now longer
being used.
We might have to think about this again if we want to allow .af files
with custom commands (e.g. shell scripts). Maybe those could get away
with just an "Icon" entry under "[App]", but currently there's only
"Executable" anyway.
