Standarize drawing stickers of a twisty puzzle. From now on, there's no 'sticker drawing' code in the individual classes, only some constants.
Convert the last 'special' case, the Rex edge sticker, to the generic sticker mechanism.
New sticker mechanism: improvements for concave stickers.
Convert the Rex corner sticker to the new mechanism.
Remove debugging.
Generalize FactorySticker - make it possible to draw stickers whose sides are curved.Convert the Ivy to use this new functionality.
improvements for FactorySticker
Move all the special cubit-creating code out of FactoryCubit and to the Object classes, and thus hopefully finish implementing the new cubit creating engine.
Move Factories to the 'helpers' package.