Ore Additions: Tin and Zinc

Adds tin and zinc as ores. Also allows the player to craft brass and bronze using a custom smithing recipe. The goal of this mod is to make resource collection less boring in a semi-vanilla way. The materials added are largely only useful for replacing vanilla crafting components. For instance, one can now craft a bucket using tin. Pistons are craftable using brass instead of iron. Rails can be crafted from bronze. Bronze tools and armor has the same (or similar) properties to iron but is less durable. Brass gears can be used instead of quartz in most Redstone components.