Removed ModDelta owner from ItemMaterial. I want to add other mod
materials like Thaumium, or Manylyumnasdadasd, (or even Nucleur Ominom,
sounds like a great material name :P). Those mods are not extending
ModDelta. Instead we should handle the mods of the Items by the mod that
implements them. e.g. ItemDeltaShovel is part of DeltaCore,
ItemBattleaxe is part of TuxWeapons, instead of saying Thaumium
ItemBattleaxe is part of Thaumcraft when ItemBattleaxe code is part of
TuxWeapons.