Wrap core functionality in an each function

If we have many DOM elements that match the PerfectScrollbar selector,
then all elemets get scrolled if one of them is scrolled.

src/perfect-scrollbar.js

@@ -11,6 +11,7 @@
 
   $.fn.perfectScrollbar = function (suppliedSettings, option) {
 
+    return this.each(function() {
       // Use the default settings
       var settings = $.extend(true, {}, defaultSettings);
       if (typeof suppliedSettings === "object") {
@@ -320,5 +321,6 @@
       initialize();
 
       return $this;
+    });
   };
 })(jQuery));