Add BlockMobSpawner and BlockOre for diff visibility

src/main/java/net/minecraft/server/BlockMobSpawner.java

@@ -0,0 +1,33 @@
+package net.minecraft.server;
+
+import java.util.Random;
+
+public class BlockMobSpawner extends BlockContainer {
+
+    protected BlockMobSpawner(int i, int j) {
+        super(i, j, Material.STONE);
+    }
+
+    public TileEntity a(World world) {
+        return new TileEntityMobSpawner();
+    }
+
+    public int getDropType(int i, Random random, int j) {
+        return 0;
+    }
+
+    public int a(Random random) {
+        return 0;
+    }
+
+    public void dropNaturally(World world, int i, int j, int k, int l, float f, int i1) {
+        super.dropNaturally(world, i, j, k, l, f, i1);
+        int j1 = 15 + world.random.nextInt(15) + world.random.nextInt(15);
+
+        this.g(world, i, j, k, j1);
+    }
+
+    public boolean d() {
+        return false;
+    }
+}