Fixed stone card exploit

More inventory logic fixes for future usage

Fixed Jokers not being correctly revealed.

Blank Vouchers are now gulped automatically, and are now effective even inside the mineshaft

Inventory logic revamped for future jokers.

(The original code was written in AB+ style, so we had to completely rewrite the entire code to fix the bugs.)

OOps (again)

Oops

Fixed Blank Voucher not re-evaluating on-demand

Added Blank Voucher, a new trinket to compensate for the recently introduced inventory limit.

It grants +5 Joker slots when held.

K&G Compat: Pocketcat Daan now sells Jimbo's Collection for 4 severed head pickups

MAJOR BUG FIX:
>Jokers now have an inventory limit of 10 jokers. The oldest joker in the inventory will be overwritten if Isaac uses another joker.
>Tainted Isaac can no longer exploit his inventory mechanic to infinitely spawn pickups.
>FIre Mind and Bozo no longer crashes the game
>Now Co-Op compatible!
>Balanced some Jokers
>RNG events are now seeded