remove system property for book size limits

"It was from a different time before books were as jank as they are now. As time has gone on they've only proven to be worse and worse."

patches/server/0400-Expose-MinecraftServer-isRunning.patch

@@ -0,0 +1,22 @@
+From 0000000000000000000000000000000000000000 Mon Sep 17 00:00:00 2001
+From: JRoy <joshroy126@gmail.com>
+Date: Fri, 10 Apr 2020 21:24:12 -0400
+Subject: [PATCH] Expose MinecraftServer#isRunning
+
+This allows for plugins to detect if the server is actually turning off in onDisable rather than just plugins reloading.
+
+diff --git a/src/main/java/org/bukkit/craftbukkit/CraftServer.java b/src/main/java/org/bukkit/craftbukkit/CraftServer.java
+index bc5034eff1e9d41c97a210b3b53c188395cb2574..2c8c800f04793493515782722d706db6e5f861af 100644
+--- a/src/main/java/org/bukkit/craftbukkit/CraftServer.java
++++ b/src/main/java/org/bukkit/craftbukkit/CraftServer.java
+@@ -2378,5 +2378,10 @@ public final class CraftServer implements Server {
+     public int getCurrentTick() {
+         return net.minecraft.server.MinecraftServer.currentTick;
+     }
++
++    @Override
++    public boolean isStopping() {
++        return net.minecraft.server.MinecraftServer.getServer().hasStopped();
++    }
+     // Paper end
+ }