More Improvements to Chunks

Fixed issues where urgent and prioritized chunks didn't actually
always get their priority boosted correctly....

Properly deprioritize non ticking chunks.
Limit recursion on watchdog prints to stop flooding as much
Remove neighbor priorities from watchdog to reduce information
reduce synchronization duration so that watch dog won't block main should main actually wake up
probably fixed a deadlock risk in watchdog printing also that was leading to crashes
fixed chunk holder enqueues not being processed correctly
added async catchers in some locations that should not be ran async

Fixed upstream bug where VITAL callbacks that must run on main actually could
sometimes run on the server thread pool causing alot of these nasty bugs we've seen lately!

This build will provide massive improvements to stability as well as even faster
sync chunk load/gens now that priority is correctly set.

Fixes #3435

Spigot-Server-Patches/String-based-Action-Bar-API.patch

@@ -4,43 +4,6 @@ Date: Tue, 27 Dec 2016 15:02:42 -0500
 Subject: [PATCH] String based Action Bar API
 
 
-diff --git a/src/main/java/net/minecraft/server/MCUtil.java b/src/main/java/net/minecraft/server/MCUtil.java
-index 0000000000000000000000000000000000000000..0000000000000000000000000000000000000000 100644
---- a/src/main/java/net/minecraft/server/MCUtil.java
-+++ b/src/main/java/net/minecraft/server/MCUtil.java
-@@ -0,0 +0,0 @@ package net.minecraft.server;
- 
- import com.destroystokyo.paper.block.TargetBlockInfo;
- import com.google.common.util.concurrent.ThreadFactoryBuilder;
-+import org.apache.commons.lang.exception.ExceptionUtils;
- import org.bukkit.Location;
- import org.bukkit.block.BlockFace;
- import org.bukkit.craftbukkit.CraftWorld;
-@@ -0,0 +0,0 @@ public final class MCUtil {
- 
-     private MCUtil() {}
- 
-+    /**
-+     * Quickly generate a stack trace for current location
-+     *
-+     * @return Stacktrace
-+     */
-+    public static String stack() {
-+        return ExceptionUtils.getFullStackTrace(new Throwable());
-+    }
-+
-+    /**
-+     * Quickly generate a stack trace for current location with message
-+     *
-+     * @param str
-+     * @return Stacktrace
-+     */
-+    public static String stack(String str) {
-+        return ExceptionUtils.getFullStackTrace(new Throwable(str));
-+    }
- 
-     public static boolean isMainThread() {
-         return MinecraftServer.getServer().isMainThread();
 diff --git a/src/main/java/org/bukkit/craftbukkit/entity/CraftPlayer.java b/src/main/java/org/bukkit/craftbukkit/entity/CraftPlayer.java
 index 0000000000000000000000000000000000000000..0000000000000000000000000000000000000000 100644
 --- a/src/main/java/org/bukkit/craftbukkit/entity/CraftPlayer.java