If a subclass of CachingSurfaceManager (and no the 'remote/offscreen' kind)
has more than one accelerated surface (for example, if the image was
blitted to different screens), it's possible to get into situation
when some of these surfaces will not get updated when the default
surface was rendered to.

This happens because CSM.copyDefaultToAccelerated updates only
the current accelerated surface (sdAccel), and clears the
dirty state of the default surface.

So if we then render this image to a different screen, an accelerated
surface associated with this screen will be used, but it won't be updated
because the default surface is marked 'clean'.

This is a regression since 1.4.2.

###@###.### 2004-05-04