Added StateHoldr::addCollectionChange
Added StateHoldr::addCollectionChange

This will be used to let OakParcelPickup be able to tell Oak to trigger
OakParcelDelivery.

gpnoel/FullScreenPokemon,edwardpark/FullScreenPokemon,dlingenau/FullScreenPokemon,dlingenau/FullScreenPokemon,syo/FullScreenPokemon,gpnoel/FullScreenPokemon,dlingenau/FullScreenPokemon,edwardpark/FullScreenPokemon,edwardpark/FullScreenPokemon,FullScreenShenanigans/FullScreenPokemon,syo/FullScreenPokemon,gpnoel/FullScreenPokemon,FullScreenShenanigans/FullScreenPokemon