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/0638-Add-Block-isValidTool.patch

@@ -0,0 +1,20 @@
+From 0000000000000000000000000000000000000000 Mon Sep 17 00:00:00 2001
+From: Jake Potrebic <jake.m.potrebic@gmail.com>
+Date: Mon, 6 Jul 2020 12:44:31 -0700
+Subject: [PATCH] Add Block#isValidTool
+
+
+diff --git a/src/main/java/org/bukkit/craftbukkit/block/CraftBlock.java b/src/main/java/org/bukkit/craftbukkit/block/CraftBlock.java
+index 2379b61fff76fa39a37348a740ca5ad18fadff4f..4270431061b5a52d709b7db4ebc8c322bdd7cfdb 100644
+--- a/src/main/java/org/bukkit/craftbukkit/block/CraftBlock.java
++++ b/src/main/java/org/bukkit/craftbukkit/block/CraftBlock.java
+@@ -819,5 +819,9 @@ public class CraftBlock implements Block {
+         }
+         return speed;
+     }
++
++    public boolean isValidTool(ItemStack itemStack) {
++        return getDrops(itemStack).size() != 0;
++    }
+     // Paper end
+ }