Added OfflinePlayer.getPlayer() for getting the online Player object

By: Nathan Adams <dinnerbone@dinnerbone.com>

paper-api/src/main/java/org/bukkit/OfflinePlayer.java

@@ -2,6 +2,7 @@ package org.bukkit;
 
 import org.bukkit.configuration.serialization.ConfigurationSerializable;
 import org.bukkit.entity.AnimalTamer;
+import org.bukkit.entity.Player;
 import org.bukkit.permissions.ServerOperator;
 
 public interface OfflinePlayer extends ServerOperator, AnimalTamer, ConfigurationSerializable {
@@ -46,4 +47,14 @@ public interface OfflinePlayer extends ServerOperator, AnimalTamer, Configuratio
      * @param value true if whitelisted
      */
     public void setWhitelisted(boolean value);
+    
+    /**
+     * Gets a {@link Player} object that this represents, if there is one
+     * <p>
+     * If the player is online, this will return that player. Otherwise,
+     * it will return null.
+     * 
+     * @return Online player
+     */
+    public Player getPlayer();
 }