Implement mod of Repulsor from Armory (Gravity shield that stacks, DR=stacksize). Refactor how stuff is placed (Don't place(player, new Thing(card, player)) instead new Thing(card, player).place() which has special handling of additive stacking) which simplifies Steal/summon. Also allow for multiple statuses, and statuses to assign values (eg charges). & on all that use equals in tests because it's nice to know what something was when it wasn't what you thought it'd be