Fixed bug in Magical Furnace -- no longer consumes entire input stack
for one operation.  Error was in smeltItem().  Condition
"if(this.furnaceItemStacks[0].stackSize >= 0)" is now
"if(this.furnaceItemStacks[0].stackSize <= 0)".

Also fixed Magical Furnace fuel in ContainermagicalFurnace to match
Vanilla Furnace fuel.