Properly fix JavaDoc linting issues

Fixes our own, and upstream's, issues with the stricter Java 8 JavaDoc
linter.

Also removes the destroystokyo-release maven repository. I'm not sure
why I added it originally, but it's unnecessary now.

Spigot-API-Patches/0047-PlayerTeleportEndGatewayEvent.patch

@@ -1,4 +1,4 @@
-From 6f53556434c1c5c59e2642b0534ff0a5854e4d50 Mon Sep 17 00:00:00 2001
+From 5a007aa00644c0fc23b76553bd92756e5517eaf1 Mon Sep 17 00:00:00 2001
 From: Aikar <aikar@aikar.co>
 Date: Sat, 31 Dec 2016 20:29:33 -0500
 Subject: [PATCH] PlayerTeleportEndGatewayEvent
@@ -7,10 +7,10 @@ Allows you to access the Gateway being used in a teleport event
 
 diff --git a/src/main/java/com/destroystokyo/paper/event/player/PlayerTeleportEndGatewayEvent.java b/src/main/java/com/destroystokyo/paper/event/player/PlayerTeleportEndGatewayEvent.java
 new file mode 100644
-index 0000000..84eb0a5
+index 00000000..bdefbc9f
 --- /dev/null
 +++ b/src/main/java/com/destroystokyo/paper/event/player/PlayerTeleportEndGatewayEvent.java
-@@ -0,0 +1,26 @@
+@@ -0,0 +1,27 @@
 +package com.destroystokyo.paper.event.player;
 +
 +import org.bukkit.Location;
@@ -31,12 +31,13 @@ index 0000000..84eb0a5
 +
 +    /**
 +     * The gateway triggering the teleport
-+     * @return
++     *
++     * @return EndGateway used
 +     */
 +    public EndGateway getGateway() {
 +        return gateway;
 +    }
 +}
 -- 
-2.9.3
+2.13.0.windows.1