Resource Titles, ActionBar, & TabTitles

I'd tip you with Reflection aswell.
Create two parts.
One which is much easier, and one which is harder with reflection.

 

!! NMS && REFLECTION !!

Made a class for you which will persist through updates and such.

Spoiler: Class

Code (Java):

public static final class Packets
{
    private Class<?> craftPlayer;
    private Method craftHandle;
    private Class<?> iChat;
    private Class<?> chatSer;
    private Method chatSerA;
    private Class<?> packetClass;

    public static String getServerVersion ()
    {
        return Bukkit.getServer ().getClass ().getPackage ().getName ().substring (23);
    }

    public static Class<?> getNMS(String name) throws Exception
    {
        return Class.forName ("net.minecraft.server." + getServerVersion () + "." + name);
    }

    public Packets ()
    {
        try
        {
            craftPlayer = Class.forName("org.bukkit.craftbukkit." + getServerVersion () + ".entity.CraftPlayer");
            craftHandle = craftPlayer.getMethod ("getHandle");
            iChat = getNMS ("IChatBaseComponent");
            chatSer = iChat.getDeclaredClasses ()[0];
            chatSerA = chatSer.getMethod("a", String.class);
            packetClass = getNMS("Packet");
        }
        catch (Exception e)
        {
            e.printStackTrace ();
        }
    }

    public Object getCraftPlayer(Player player)
    {
        try
        {
            return craftHandle.invoke (player);
        }
        catch (IllegalAccessException | InvocationTargetException e)
        {
            e.printStackTrace ();
        }
        return null;
    }

    public Object getConnection(Object craftPlayer)
    {
        try
        {
            return craftPlayer.getClass ().getField ("playerConnection");
        }
        catch (NoSuchFieldException e)
        {
            e.printStackTrace ();
        }
        return null;
    }

    public void sendTitle(Player player, String title, String subtitle, int fadeIn, int stay, int fadeOut)
    {
        try
        {
            Object craftPlayer = getCraftPlayer (player);
            Object connection = getConnection (craftPlayer);
            Object titl = chatSerA.invoke (title);
            Object subt = chatSerA.invoke (subtitle);
            Class<?> titlePacket = getNMS ("PacketPlayOutTitle");
            Constructor<?> titlC = ReflectionUtils.getConstructor (titlePacket, titlePacket.getDeclaredClasses ()[0], iChat, int.class, int.class, int.class);
            Constructor<?> subtC = ReflectionUtils.getConstructor (titlePacket, titlePacket.getDeclaredClasses()[0], iChat);
            Object send1 = titlC.newInstance (titlePacket.getDeclaredClasses ()[0].getEnumConstants ()[0], titl, fadeIn, stay, fadeOut);
            Object send2 = subtC.newInstance (titlePacket.getDeclaredClasses ()[0].getEnumConstants ()[1], subt);
            Method send = connection.getClass ().getMethod ("sendPacket", packetClass);
            send.invoke (connection, send1);
            send.invoke (connection, send2);
        }
        catch (Exception e)
        {
            e.printStackTrace ();
        }
    }

    public void sendTabHF(Player player, String header, String footer)
    {
        Object craftPlayer = getCraftPlayer (player);
        Object connection = getConnection (craftPlayer);
        try {
            Object headerJSON = chatSerA.invoke (header);
            Object footerJSON = chatSerA.invoke(footer);
            Object packet = getNMS ("PacketPlayOutPlayerListHeaderFooter").getConstructor ().newInstance ();
            Field headerField = packet.getClass ().getDeclaredField("a");
            headerField.setAccessible(true);
            headerField.set(packet, headerJSON);
            headerField.setAccessible(!headerField.isAccessible());

            Field footerField = packet.getClass().getDeclaredField("b");
            footerField.setAccessible(true);
            footerField.set(packet, footerJSON);
            footerField.setAccessible(!footerField.isAccessible());

            connection.getClass ().getMethod ("sendPacket", packetClass).invoke (player, packet);
        }catch (Exception e)
        {
            e.printStackTrace ();
        }
    }

    public void sendActionBar(Player player, String message)
    {
        Object craftPlayer = getCraftPlayer (player);
        Object connection = getConnection (craftPlayer);
        try {
            Class<?> packet = getNMS ("PacketPlayOutChat");
            connection.getClass ().getMethod ("sendPacket", packetClass).invoke (player, packet.getConstructor (iChat, byte.class).newInstance (chatSerA.invoke ("{\"text\": \"" + message + "\"}"), (byte)2));
        } catch (Exception e)
        {
            e.printStackTrace ();
        }
    }
}

 

Nop
Yours work with the one that they build against, and REQUIRES spigot/craftbukkit jar, and not the spigotapi/bukkit jar.
So, if they build it with the packages net.minecraft.server.V1_9_2R01, it will only work with that.
1.9.2R02 won't work with the plugin.
Mine will.