Cache BlockState for Blocks

Improve performance for many plugins that call .getState() multiple
times for things like signs that have to "build" sign data.

Spigot-Server-Patches/Cache-BlockState-for-Blocks.patch

@@ -0,0 +1,37 @@
+From 0000000000000000000000000000000000000000 Mon Sep 17 00:00:00 2001
+From: Aikar <aikar@aikar.co>
+Date: Thu, 14 Jan 2016 01:16:30 -0500
+Subject: [PATCH] Cache BlockState for Blocks
+
+Improve performance for many plugins that call .getState() multiple
+times for things like signs that have to "build" sign data.
+
+diff --git a/src/main/java/org/bukkit/craftbukkit/block/CraftBlock.java b/src/main/java/org/bukkit/craftbukkit/block/CraftBlock.java
+index 0000000000000000000000000000000000000000..0000000000000000000000000000000000000000 100644
+--- a/src/main/java/org/bukkit/craftbukkit/block/CraftBlock.java
++++ b/src/main/java/org/bukkit/craftbukkit/block/CraftBlock.java
+@@ -0,0 +0,0 @@ import org.bukkit.util.BlockVector;
+ 
+ public class CraftBlock implements Block {
+     private final CraftChunk chunk;
++    private BlockState state; // Paper
+     private final int x;
+     private final int y;
+     private final int z;
+@@ -0,0 +0,0 @@ public class CraftBlock implements Block {
+         }
+     }
+ 
++    // Paper start
+     public BlockState getState() {
++        if (this.state == null) {
++            this.state = getState0();
++        }
++        return this.state;
++    }
++    private BlockState getState0() {
++        // Paper end
+         Material material = getType();
+ 
+         switch (material) {
+--