Form Subscription

- improved MailPoet ajax to fix token issue
- added js validation and ajax submit in public.js
- add util security to generate tokens
- updated router to use new util security
- added jquery-validation module
- update public config in webpack config
- added error messages in form

lib/Models/Subscriber.php

@@ -10,16 +10,8 @@ class Subscriber extends Model {
     parent::__construct();
 
     $this->addValidations('email', array(
-      'required' => "email_is_blank",
-      'isEmail'  => "email_is_invalid"
-    ));
-    $this->addValidations('first_name', array(
-      'required'    => "first_name_is_blank",
-      "isString"    => "name_is_not_string"
-    ));
-    $this->addValidations('last_name', array(
-      'required'    => "last_name_is_blank",
-      "isString"    => "name_is_not_string"
+      'required' => __('You need to enter your email address.'),
+      'isEmail' => __('Your email address is invalid.')
     ));
   }
 }