Update from upstream SpigotMC

Upstream merge (we must go deeper) SpigotMC/Spigot@1e7bc383c3

CraftBukkit-Patches/0119-Print-Stack-on-InternalException.patch

@@ -0,0 +1,19 @@
+From 0000000000000000000000000000000000000000 Mon Sep 17 00:00:00 2001
+From: md_5 <git@md-5.net>
+Date: Sun, 13 Apr 2014 09:00:59 +1000
+Subject: [PATCH] Print Stack on InternalException
+
+
+diff --git a/src/main/java/net/minecraft/server/NetworkManager.java b/src/main/java/net/minecraft/server/NetworkManager.java
+index 0000000000000000000000000000000000000000..0000000000000000000000000000000000000000 100644
+--- a/src/main/java/net/minecraft/server/NetworkManager.java
++++ b/src/main/java/net/minecraft/server/NetworkManager.java
+@@ -0,0 +0,0 @@ public class NetworkManager extends SimpleChannelInboundHandler {
+         }
+ 
+         this.close(chatmessage);
++        if (MinecraftServer.getServer().isDebugging()) throwable.printStackTrace(); // Spigot
+     }
+ 
+     protected void a(ChannelHandlerContext channelhandlercontext, Packet packet) {
+--