Add some useful information to spawned entities.

finish adding extra pit tiles, allow rendering below and after shading.

Allow returned weight in POST_CHECK_VALID_ROOM to be overriden by later running callbacks.

Support for extra pit frames wip, disabled for now. More control over streaks.

Override spike and pit anm2s to fix being offset from grid, change wall anm2 to match base game.

Properly check for door existing in croom.

Poop variants now spawn correctly.

Select door from valid doors when entering a room with croom.

Fix _ENV usage and allow ignoring or overriding doors, for special cases.

Fix various possible alt rock spawns being deleted when entering a room if an alt rock existed at their position in the previous one.