It compiles, but this code is just unused yet.

Moved away from inheriting Engine from SuperEngine.
Idea behind SuperEngine was to introduce base class for several engines.
Well, currently there's only one.
And I think that it's better to actually create 
base-interface class when we have more than one engine at hands,
so we can look for what they have in common etc etc :).

Yesterday's problem with QGV's margin didn't go away... Oh, well

svn path=/branches/work/kreversi_rewrite/; revision=571980