Balefire Spellbook

- Changed spellbook to use mana instead of stamina

- The spellbook by default now gives you 10 mana when held and uses 5 mana for each cast (can be changed in the asset editor to fit in with other magic mods)

- Changed spellbook name to be consistent with the skeleton-summoning spellbook
- Fixed bug where player is stuck in the cast animation if there is not enough mana to cast the spell