Adds lifesteal mechanics via new enchantments and a new food item.

NEW ENCHANTMENTS

Drain life

Restores health based on a portion of damage dealt.
Maximum level: 3
Rarity: Rare
Type: Normal
Applicable to: Weapons
Formula: Damage Dealt * (1 - 0.95^X), where X = enchantment level.
If the result is less than 1, it will not apply the Drain Life effect. Otherwise the value will round up or down to the nearest neighbor.

Necrotism

Deals extra damage and restores half as much as health.
Drains 8 durability per use.
Maximum level: 4
Rarity: Rare. Not available via the enchantment table.
Type: Curse
Applicable to: Weapons
Formula (for damage): 2*X, where X = enchantment level.
This uses an unique damage type.
Health gained is equal to the enchantment level.

NEW ORE

Vitalifur Ore

Drops vitalifur when broken. Works with fortune enchantments.
Spawns between Y-64 and Y64 on stone blocks.

NEW FOOD

Vitalifur

Drops from vitalifur ore. Can always be eaten.
Restores a little bit of hunger and saturation. Also restores 2 health (1 heart).

Healing Cookie

Crafted with wheat, sugar, cocoa beans and vitalifur. This gives 8 cookies.
Restores a minimal amount of hunger and saturation. Also restores 1 health (0,5 hearts).
Can be eaten extremely fast.

NEW POTION EFFECT

Vampirism

Restores health based on a portion of damage dealt.
Potion is crafted by brewing vitalifur into mundane potion(s).
Formula: Damage Dealt * 0.1
If the result is less than 1, it will not apply the Vampirism effect. Otherwise the value will round up or down to the nearest neighbor.

For bug reporting: