SPIGOT-4674: Allow spawning hanging on top/bottom of block

src/main/java/org/bukkit/craftbukkit/CraftWorld.java

@@ -1277,7 +1277,7 @@ public class CraftWorld implements World {
                 height = 9;
             }
 
-            BlockFace[] faces = new BlockFace[]{BlockFace.EAST, BlockFace.NORTH, BlockFace.WEST, BlockFace.SOUTH};
+            BlockFace[] faces = new BlockFace[]{BlockFace.EAST, BlockFace.NORTH, BlockFace.WEST, BlockFace.SOUTH, BlockFace.UP, BlockFace.DOWN};
             final BlockPosition pos = new BlockPosition((int) x, (int) y, (int) z);
             for (BlockFace dir : faces) {
                 IBlockData nmsBlock = world.getType(pos.shift(CraftBlock.blockFaceToNotch(dir)));