0. ADD EID SUPPORT
1. Test Black Rune with J&E
2. Change berkano from 5spiders+ 10 flies to 8 spiders + 8 flies
3. Add a "purge" effect to Dagaz, removing the devil deal penalty for taking read heart damages this floor
4. Add stacking effect when holding multiple Magic Chalk (the effect is limited to a certain subset of runes)

Known bugs (won't fix most likely):

• Ehwaz when used in front of a door spawns several trapdoors
  
• Black Rune stat bonuses might act weird when several players have each a copy of Magic Chalk

Add Magic Chalk to shop and curse item pool (so that it's actually available in-game)