Add ListExtensions

src/main/kotlin/net/shadowfacts/forgelin/extensions/ListExtensions.kt

@@ -0,0 +1,15 @@
+package net.shadowfacts.forgelin.extensions
+
+import net.minecraft.item.ItemStack
+
+/**
+ * @author shadowfacts
+ */
+fun List<ItemStack>.containsStack(stack: ItemStack): Boolean {
+	forEach {
+		if (it.item == stack.item && it.itemDamage == stack.itemDamage) {
+			return true
+		}
+	}
+	return false
+}