Make ZADD and ZREM variadic commands for Redis 2.4.

lib/Predis/Commands/ZSetAdd.php

@@ -2,11 +2,17 @@
 
 namespace Predis\Commands;
 
+use Predis\Helpers;
+
 class ZSetAdd extends Command {
     public function getId() {
         return 'ZADD';
     }
 
+    protected function filterArguments(Array $arguments) {
+        return Helpers::filterVariadicValues($arguments);
+    }
+
     public function parseResponse($data) {
         return (bool) $data;
     }

lib/Predis/Commands/ZSetRemove.php

@@ -2,11 +2,17 @@
 
 namespace Predis\Commands;
 
+use Predis\Helpers;
+
 class ZSetRemove extends Command {
     public function getId() {
         return 'ZREM';
     }
 
+    protected function filterArguments(Array $arguments) {
+        return Helpers::filterVariadicValues($arguments);
+    }
+
     public function parseResponse($data) {
         return (bool) $data;
     }