Don't pass null title to constructor

Fixes #83
Fix resetTitle()
@Zbob750 shouldn't be doing these updates in the middle of the night

Spigot-Server-Patches/Player-Tab-List-and-Title-APIs.patch

@@ -100,26 +100,27 @@ index 0000000000000000000000000000000000000000..00000000000000000000000000000000
  
      @Override
 @@ -0,0 +0,0 @@ public class CraftPlayer extends CraftHumanEntity implements Player {
+ 
      @Override
      public void sendTitle(String title, String subtitle) {
-         if (title != null) {
+-        if (title != null) {
 -            PacketPlayOutTitle packetTitle = new PacketPlayOutTitle(EnumTitleAction.TITLE, CraftChatMessage.fromString(title)[0]);
 -            getHandle().playerConnection.sendPacket(packetTitle);
-+            this.sendTitle(new Title(title)); // TODO: Paper - Double check these
-         }
- 
-         if (subtitle != null) {
+-        }
+-
+-        if (subtitle != null) {
 -            PacketPlayOutTitle packetSubtitle = new PacketPlayOutTitle(EnumTitleAction.SUBTITLE, CraftChatMessage.fromString(subtitle)[0]);
 -            getHandle().playerConnection.sendPacket(packetSubtitle);
-+            this.sendTitle(new Title(null, subtitle)); // TODO: Paper - Double check these
-         }
+-        }
++        Preconditions.checkNotNull(title, "Null title");
++        this.sendTitle(new Title(title, subtitle));
      }
  
      @Override
      public void resetTitle() {
 -        PacketPlayOutTitle packetReset = new PacketPlayOutTitle(EnumTitleAction.RESET, null);
 -        getHandle().playerConnection.sendPacket(packetReset);
-+        this.hideTitle(); // TODO: Paper - Double check these
++        getHandle().playerConnection.sendPacket(new PacketPlayOutTitle(PacketPlayOutTitle.EnumTitleAction.RESET, (BaseComponent[]) null, 0, 0, 0));
      }
  
      @Override