Replaced all instances of Guava's Optional type with Java 8's Optional type, as discussed in #81. (#90)

src/main/java/appeng/container/implementations/ContainerQuartzKnife.java

@@ -24,7 +24,6 @@ import net.minecraft.entity.player.InventoryPlayer;
 import net.minecraft.inventory.IInventory;
 import net.minecraft.item.ItemStack;
 import net.minecraft.nbt.NBTTagCompound;
-import net.minecraft.util.EnumHand;
 import net.minecraft.util.text.ITextComponent;
 import net.minecraftforge.common.MinecraftForge;
 import net.minecraftforge.event.entity.player.PlayerDestroyItemEvent;
@@ -138,13 +137,13 @@ public class ContainerQuartzKnife extends AEBaseContainer implements IAEAppEngIn
 		{
 			if( this.myName.length() > 0 )
 			{
-				for( final ItemStack namePressStack : AEApi.instance().definitions().materials().namePress().maybeStack( 1 ).asSet() )
+				return AEApi.instance().definitions().materials().namePress().maybeStack( 1 ).map( namePressStack ->
 				{
 					final NBTTagCompound compound = Platform.openNbtData( namePressStack );
 					compound.setString( "InscribeName", this.myName );
 
 					return namePressStack;
-				}
+				} ).orElse( null );
 			}
 		}