[CurveCalc] fixed z-ordering problem

+ all Z values are now instantly changed (slope = Infinity)
[CurveCalc] fixing slopes

+ inSlopes of the next frame for position and scale are now outSlopes
of the previous frames
+ this fixes various problems with scales (mainly seen on pickups)
[PrefabMaker] fix for scales of pivots

+ this partially solves “the coin problem”
+ basic animations with just sprites should work fine
[examples] update for Crabby

+ crabby regenerated using the newest version of converter
[PrefabMaker] fix for pivot scales

+ multiplying whole scale BEFORE rotation
+ regenerated Crabby once again