New functions added to easily add and remove (max)mana:

Increase a Players maximum Mana amount:
ManaApi.addMaxMana(Player player, int amount)

Decrease a Players maximum Mana amount:
ManaApi.removeMaxMana(Player player, int amount)

Increase a Players current Mana amount:
ManaApi.addCurrentMana(Player player, int amount)

Decrease a Players current Mana amount:
ManaApi.removeCurrentMana(Player player, int amount)