Add more general item colouring system

This allows for other items, such as turtles, to be dyed in the future.
This also adds support for the ore dictionary, meaning you can use other
mod's dyes to colour items.

src/main/java/dan200/computercraft/shared/common/ColourableRecipe.java

@@ -0,0 +1,106 @@
+package dan200.computercraft.shared.common;
+
+import dan200.computercraft.shared.util.Colour;
+import dan200.computercraft.shared.util.ColourTracker;
+import dan200.computercraft.shared.util.ColourUtils;
+import net.minecraft.inventory.InventoryCrafting;
+import net.minecraft.item.ItemStack;
+import net.minecraft.item.crafting.IRecipe;
+import net.minecraft.world.World;
+import net.minecraftforge.common.ForgeHooks;
+
+import javax.annotation.Nonnull;
+import javax.annotation.Nullable;
+
+public class ColourableRecipe implements IRecipe
+{
+    @Override
+    public boolean matches( @Nonnull InventoryCrafting inv, @Nonnull World worldIn )
+    {
+        boolean hasColourable = false;
+        boolean hasDye = false;
+        for( int i = 0; i < inv.getSizeInventory(); i++ )
+        {
+            ItemStack stack = inv.getStackInSlot( i );
+            if( stack == null ) continue;
+
+            if( stack.getItem() instanceof IColouredItem )
+            {
+                if( hasColourable ) return false;
+                hasColourable = true;
+            }
+            else if( ColourUtils.getStackColour( stack ) >= 0 )
+            {
+                hasDye = true;
+            }
+            else
+            {
+                return false;
+            }
+        }
+
+        return hasColourable && hasDye;
+    }
+
+    @Nullable
+    @Override
+    public ItemStack getCraftingResult( @Nonnull InventoryCrafting inv )
+    {
+        ItemStack colourable = null;
+
+        ColourTracker tracker = new ColourTracker();
+
+        for( int i = 0; i < inv.getSizeInventory(); ++i )
+        {
+            ItemStack stack = inv.getStackInSlot( i );
+
+            if( stack == null ) continue;
+
+            if( stack.getItem() instanceof IColouredItem )
+            {
+                colourable = stack;
+            }
+            else
+            {
+                int index = ColourUtils.getStackColour( stack );
+                if( index < 0 ) continue;
+
+                Colour colour = Colour.values()[ index ];
+                tracker.addColour( colour.getR(), colour.getG(), colour.getB() );
+            }
+        }
+
+        if( colourable == null )
+        {
+            return null;
+        }
+
+        return ((IColouredItem) colourable.getItem()).setColour( colourable, tracker.getColour() );
+    }
+
+    @Override
+    public int getRecipeSize()
+    {
+        return 2;
+    }
+
+    @Nullable
+    @Override
+    public ItemStack getRecipeOutput()
+    {
+        return null;
+    }
+
+    @Nonnull
+    @Override
+    public ItemStack[] getRemainingItems( @Nonnull InventoryCrafting inv )
+    {
+        ItemStack[] results = new ItemStack[ inv.getSizeInventory() ];
+        for( int i = 0; i < results.length; ++i )
+        {
+            ItemStack stack = inv.getStackInSlot( i );
+            results[ i ] = ForgeHooks.getContainerItem( stack );
+        }
+        return results;
+    }
+}