Allow proto chunks to be saved again

Appear to be used more extensively in 1.14. Subject to further review.

Spigot-Server-Patches/0375-Server-Tick-Events.patch

@@ -0,0 +1,34 @@
+From 5ceffba14f8451560d802a47305c50d9a1912696 Mon Sep 17 00:00:00 2001
+From: Aikar <aikar@aikar.co>
+Date: Wed, 27 Mar 2019 22:48:45 -0400
+Subject: [PATCH] Server Tick Events
+
+Fires event at start and end of a server tick
+
+diff --git a/src/main/java/net/minecraft/server/MinecraftServer.java b/src/main/java/net/minecraft/server/MinecraftServer.java
+index 99306781f..cbb428063 100644
+--- a/src/main/java/net/minecraft/server/MinecraftServer.java
++++ b/src/main/java/net/minecraft/server/MinecraftServer.java
+@@ -1041,6 +1041,7 @@ public abstract class MinecraftServer extends IAsyncTaskHandlerReentrant<TickTas
+         co.aikar.timings.TimingsManager.FULL_SERVER_TICK.startTiming(); // Paper
+         this.slackActivityAccountant.tickStarted(); // Spigot
+         long i = SystemUtils.getMonotonicNanos();
++        new com.destroystokyo.paper.event.server.ServerTickStartEvent(this.ticks+1).callEvent(); // Paper
+ 
+         ++this.ticks;
+         this.b(booleansupplier);
+@@ -1087,6 +1088,11 @@ public abstract class MinecraftServer extends IAsyncTaskHandlerReentrant<TickTas
+         this.methodProfiler.exit();
+         org.spigotmc.WatchdogThread.tick(); // Spigot
+         this.slackActivityAccountant.tickEnded(l); // Spigot
++        // Paper start
++        long endTime = System.nanoTime();
++        long remaining = (TICK_TIME - (endTime - lastTick)) - catchupTime;
++        new com.destroystokyo.paper.event.server.ServerTickEndEvent(this.ticks, ((double)(endTime - lastTick) / 1000000D), remaining).callEvent();
++        // Paper end
+         co.aikar.timings.TimingsManager.FULL_SERVER_TICK.stopTiming(); // Paper
+     }
+ 
+-- 
+2.21.0
+