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/Disable-explosion-knockback.patch

@@ -5,7 +5,7 @@ Subject: [PATCH] Disable explosion knockback
 
 
 diff --git a/src/main/java/com/destroystokyo/paper/PaperWorldConfig.java b/src/main/java/com/destroystokyo/paper/PaperWorldConfig.java
-index b5a106d5b..fcbf8a25c 100644
+index a197af84f..2217f680c 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 {
@@ -19,7 +19,7 @@ index b5a106d5b..fcbf8a25c 100644
 +    }
  }
 diff --git a/src/main/java/net/minecraft/server/EntityLiving.java b/src/main/java/net/minecraft/server/EntityLiving.java
-index 4fbe92a5a..b959fdac8 100644
+index b22f81b12..e5fa1c3ba 100644
 --- a/src/main/java/net/minecraft/server/EntityLiving.java
 +++ b/src/main/java/net/minecraft/server/EntityLiving.java
 @@ -0,0 +0,0 @@ public abstract class EntityLiving extends Entity {