staticGet is a static function

We always call staticGet statically, so we define it statically. Next
step is to remove a bunch of definitions of 'staticGet' from classes
that can instead fall back to a parent class in Managed_DataObject.

The ampersand is removed as we're returning a class anyway, which does
not need a reference (and when we return false, it means nothing).

classes/Memcached_DataObject.php

@@ -30,7 +30,7 @@ class Memcached_DataObject extends Safe_DataObject
      * @param mixed $v key field value, or leave out for primary key lookup
      * @return mixed Memcached_DataObject subtype or false
      */
-    function &staticGet($cls, $k, $v=null)
+    static function staticGet($cls, $k, $v=null)
     {
         if (is_null($v)) {
             $v = $k;