Update upstream B/CB/S

Adds /paper command for reloading the paper config.
Closes GH-639

Per-world config logging has been removed in favor of all or nothing
logging for all paper settings. I don't believe it was used enough to
warrant maintaining. If this is not the case it should be possible to
re-add it.

Spigot-Server-Patches/Optimize-explosions.patch

@@ -10,7 +10,7 @@ This patch adds a per-tick cache that is used for storing and retrieving
 an entity's exposure during an explosion.
 
 diff --git a/src/main/java/com/destroystokyo/paper/PaperWorldConfig.java b/src/main/java/com/destroystokyo/paper/PaperWorldConfig.java
-index bc5028965..356265e91 100644
+index 3b19b53a8..a7dfd2af7 100644
 --- a/src/main/java/com/destroystokyo/paper/PaperWorldConfig.java
 +++ b/src/main/java/com/destroystokyo/paper/PaperWorldConfig.java
 @@ -0,0 +0,0 @@ public class PaperWorldConfig {
@@ -124,7 +124,7 @@ index 4e05bcdfa..49fc95e35 100644
 +    // Paper end
  }
 diff --git a/src/main/java/net/minecraft/server/MinecraftServer.java b/src/main/java/net/minecraft/server/MinecraftServer.java
-index 1d9ba0d0f..b3454eae6 100644
+index f953ef8e0..3b67ff52e 100644
 --- a/src/main/java/net/minecraft/server/MinecraftServer.java
 +++ b/src/main/java/net/minecraft/server/MinecraftServer.java
 @@ -0,0 +0,0 @@ public abstract class MinecraftServer implements Runnable, ICommandListener, IAs
@@ -136,7 +136,7 @@ index 1d9ba0d0f..b3454eae6 100644
  
              // this.i[i][this.ticks % 100] = System.nanoTime() - j; // CraftBukkit
 diff --git a/src/main/java/net/minecraft/server/World.java b/src/main/java/net/minecraft/server/World.java
-index b38228707..ea6f02a68 100644
+index e6e85e7a8..5f7590e11 100644
 --- a/src/main/java/net/minecraft/server/World.java
 +++ b/src/main/java/net/minecraft/server/World.java
 @@ -0,0 +0,0 @@ import javax.annotation.Nullable;