Toggleable player crits, helps mitigate hacked clients. (#1040)

This is a port of https://github.com/PaperMC/Paper/blob/ver/1.8.8/Spigot-Server-Patches/0040-Toggleable-player-crits-helps-mitigate-hacked-client.patch
Also adds me to the MIT list.

Spigot-API-Patches/Add-MetadataStoreBase.removeAll-Plugin.patch

@@ -6,14 +6,13 @@ Subject: [PATCH] Add MetadataStoreBase.removeAll(Plugin)
 So that on reload, metadata will be cleared
 
 diff --git a/src/main/java/org/bukkit/metadata/MetadataStoreBase.java b/src/main/java/org/bukkit/metadata/MetadataStoreBase.java
-index 64c0f0a7..6da6abd8 100644
+index 0000000000000000000000000000000000000000..0000000000000000000000000000000000000000 100644
 --- a/src/main/java/org/bukkit/metadata/MetadataStoreBase.java
 +++ b/src/main/java/org/bukkit/metadata/MetadataStoreBase.java
 @@ -0,0 +0,0 @@ public abstract class MetadataStoreBase<T> {
-         }
      }
  
-+    /**
+     /**
 +     * Removes all metadata in the metadata store that originates from the
 +     * given plugin.
 +     *
@@ -33,7 +32,8 @@ index 64c0f0a7..6da6abd8 100644
 +        }
 +    }
 +
-     /**
++    /**
       * Creates a unique name for the object receiving metadata by combining
       * unique data from the subject with a metadataKey.
+      * <p>
 --