First batch of null -> isEmpty() checks.

I most likely still missed a ton of checks...

src/main/java/appeng/facade/FacadeContainer.java

@@ -165,7 +165,7 @@ public class FacadeContainer implements IFacadeContainer
 			if( t != null )
 			{
 				final ItemStack is = new ItemStack( t );
-				if( is != null )
+				if( !is.isEmpty() )
 				{
 					final Item i = is.getItem();
 					if( i instanceof IFacadeItem )

src/main/java/appeng/facade/FacadePart.java

@@ -88,7 +88,7 @@ public class FacadePart implements IFacadePart, IBoxProvider
 	public Item getItem()
 	{
 		final ItemStack is = this.getTextureItem();
-		if( is == null )
+		if( is.isEmpty() )
 		{
 			return null;
 		}
@@ -99,7 +99,7 @@ public class FacadePart implements IFacadePart, IBoxProvider
 	public int getItemDamage()
 	{
 		final ItemStack is = this.getTextureItem();
-		if( is == null )
+		if( is.isEmpty() )
 		{
 			return 0;
 		}