Rework AEItemStack (#3091)

* Use itemstack as itemdef
* HIGH_TAG/LOW_TAG should be compared both directions
* Remove getTagCompound
* Make Itemlist implementation independent
* Cache item id for performance reasons
* Add preconditions to saveguard against external meddling
* Chache itemDamage
* Remove IAEStackSearchKey for now, rename getDisplayStack

src/main/java/appeng/helpers/PatternHelper.java

@@ -334,7 +334,7 @@ public class PatternHelper implements ICraftingPatternDetails, Comparable<Patter
 
 		if( this.outputs != null && this.outputs.length > 0 )
 		{
-			return this.outputs[0].getItemStack();
+			return this.outputs[0].createItemStack();
 		}
 
 		return ItemStack.EMPTY;