Implement stack.effectiveIndex, which does the logic for what the {First,Last}{Component,Slot}Index resolve to for a given stack. Not tested. Part of #179.
Implement stack.effectiveIndex, which does the logic for what the {First,Last}{Component,Slot}Index resolve to for a given stack. Not tested. Part of #179.

jkomoros/boardgame,jkomoros/boardgame,jkomoros/boardgame