The "spawner|mobType" syntax once again makes functional mob spawners.

Also fix block parser context not being restricted.

worldedit-core/src/main/java/com/sk89q/worldedit/command/argument/FactoryConverter.java

@@ -81,6 +81,7 @@ public class FactoryConverter<T> implements ArgumentConverter<T> {
             }
         }
         parserContext.setSession(session);
+        parserContext.setRestricted(true);
 
         try {
             return SuccessfulConversion.fromSingle(