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/util/inv/AdaptorList.java

@@ -190,7 +190,7 @@ public class AdaptorList extends InventoryAdaptor
 
 		for( final ItemStack is : this.i )
 		{
-			if( Platform.itemComparisons().isEqualItem( is, left ) )
+			if( ItemStack.areItemsEqual( is, left ) )
 			{
 				is.grow( left.getCount() );
 				return ItemStack.EMPTY;

src/main/java/appeng/util/inv/IMEAdaptor.java

@@ -99,7 +99,7 @@ public class IMEAdaptor extends InventoryAdaptor
 
 		if( out != null )
 		{
-			return out.getItemStack();
+			return out.createItemStack();
 		}
 
 		return ItemStack.EMPTY;
@@ -139,7 +139,7 @@ public class IMEAdaptor extends InventoryAdaptor
 				out = this.target.extractItems( req, type, this.src );
 				if( out != null )
 				{
-					return out.getItemStack();
+					return out.createItemStack();
 				}
 			}
 		}
@@ -166,7 +166,7 @@ public class IMEAdaptor extends InventoryAdaptor
 			final IAEItemStack out = this.target.injectItems( in, Actionable.MODULATE, this.src );
 			if( out != null )
 			{
-				return out.getItemStack();
+				return out.createItemStack();
 			}
 		}
 		return ItemStack.EMPTY;
@@ -181,7 +181,7 @@ public class IMEAdaptor extends InventoryAdaptor
 			final IAEItemStack out = this.target.injectItems( in, Actionable.SIMULATE, this.src );
 			if( out != null )
 			{
-				return out.getItemStack();
+				return out.createItemStack();
 			}
 		}
 		return ItemStack.EMPTY;

src/main/java/appeng/util/inv/ItemSlot.java

@@ -37,7 +37,7 @@ public class ItemSlot
 	public ItemStack getItemStack()
 	{
 		return this.itemStack
-				.isEmpty() ? ( this.aeItemStack == null ? ItemStack.EMPTY : ( this.itemStack = this.aeItemStack.getItemStack() ) ) : this.itemStack;
+				.isEmpty() ? ( this.aeItemStack == null ? ItemStack.EMPTY : ( this.itemStack = this.aeItemStack.createItemStack() ) ) : this.itemStack;
 	}
 
 	public void setItemStack( final ItemStack is )