Summary of today's changes:
* All visible CanvasItems (except for Ball) have now been refactored.
* All CanvasItems allow on-screen editing via Kolf::Overlay now.
Regressions:
* Z ordering is completely broken, and will be rewritten tomorrow.
* I have not tested load/save yet, though there seem to be some minor issues.
* The editor behaves a bit awkwardly because KolfGame still does its own selection stuff.

svn path=/trunk/KDE/kdegames/kolf/; revision=1195400