Initial Paper-API for Bukkit 1.13 Preview 4 - THIS IS NOT SERVER

This branch/commit is only useful to those who purely use a clean Bukkit/Spigot/Paper API
and does not use NMS/OBC references.

This will let you start updating your plugin to the latest 1.13 builds of Bukkit Preview (4 as of now)

Note that this release is not final!!! API breakages may occur!

It is up to you if you find use out of this work.

pre/Bukkit-Patches/0014-Add-Getter-for-Entity-Invulnerability.patch

@@ -0,0 +1,27 @@
+From 0000000000000000000000000000000000000000 Mon Sep 17 00:00:00 2001
+From: md_5 <md_5@live.com.au>
+Date: Sat, 3 Aug 2013 19:49:36 +1000
+Subject: [PATCH] Add Getter for Entity Invulnerability
+
+
+diff --git a/src/main/java/org/bukkit/entity/Entity.java b/src/main/java/org/bukkit/entity/Entity.java
+index 294eb7f7..28b169d2 100644
+--- a/src/main/java/org/bukkit/entity/Entity.java
++++ b/src/main/java/org/bukkit/entity/Entity.java
+@@ -0,0 +0,0 @@ public interface Entity extends Metadatable, CommandSender, Nameable {
+     public class Spigot extends CommandSender.Spigot
+     {
+ 
++        /**
++         * Returns whether this entity is invulnerable.
++         *
++         * @return True if the entity is invulnerable.
++         */
++        public boolean isInvulnerable()
++        {
++            throw new UnsupportedOperationException( "Not supported yet." );
++        }
+     }
+ 
+     @Override
+--