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/Make-entities-look-for-hoppers.patch

@@ -78,7 +78,7 @@ index 000000000..aef7c2be9
 +    double getZ();
 +}
 diff --git a/src/main/java/com/destroystokyo/paper/PaperWorldConfig.java b/src/main/java/com/destroystokyo/paper/PaperWorldConfig.java
-index a57a3971f..b9b0f7479 100644
+index 7bd745a27..894d40662 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 {
@@ -132,7 +132,7 @@ index 008ed206d..b3c1f550c 100644
              this.b = i;
              this.c = j;
 diff --git a/src/main/java/net/minecraft/server/Entity.java b/src/main/java/net/minecraft/server/Entity.java
-index 40a7df117..916d5e266 100644
+index 0d1fdd3ee..0479b7551 100644
 --- a/src/main/java/net/minecraft/server/Entity.java
 +++ b/src/main/java/net/minecraft/server/Entity.java
 @@ -0,0 +0,0 @@ public abstract class Entity implements ICommandListener {