Add material data classes for cake, jukeboxes, and diodes. Remove some unneeded ones.

src/main/java/org/bukkit/material/Cake.java

@@ -0,0 +1,61 @@
+package org.bukkit.material;
+
+import org.bukkit.Material;
+
+public class Cake extends MaterialData {
+
+    public Cake(int type) {
+        super(type);
+    }
+
+    public Cake(Material type) {
+        super(type);
+    }
+
+    public Cake(int type, byte data) {
+        super(type, data);
+    }
+
+    public Cake(Material type, byte data) {
+        super(type, data);
+    }
+
+    /**
+     * Gets the number of slices eaten from this cake
+     * 
+     * @return The number of slices eaten
+     */
+    public int getSlicesEaten() {
+        return getData();
+    }
+
+    /**
+     * Gets the number of slices remaining on this cake
+     * 
+     * @return The number of slices remaining
+     */
+    public int getSlicesRemaining() {
+        return 6 - getData();
+    }
+
+    /**
+     * Sets the number of slices eaten from this cake
+     * 
+     * @param n The number of slices eaten
+     */
+    public void setSlicesEaten(int n) {
+        if (n < 6) {
+            setData((byte) n);
+        } // TODO: else destroy the block? Probably not possible though
+    }
+
+    /**
+     * Sets the number of slices remaining on this cake
+     * 
+     * @param n The number of slices remaining
+     */
+    public void setSlicesRemaining(int n) {
+        if (n > 6) n = 6;
+        setData((byte) (6 - n));
+    }
+}