Added MappedSuperclass for spooled SMS

This will be used later

Model/SpooledSms.php

@@ -0,0 +1,50 @@
+<?php
+namespace BrokernetGroup\Common\SMSSenderBundle\Model;
+
+use Doctrine\ORM\Mapping as ORM;
+
+/**
+ * Entity to spool SMS messages
+ *
+ * @ORM\MappedSuperclass
+ */
+class SpooledSms
+{
+    /**
+     * The recipient's mobile phone number
+     *
+     * @var string $recipient
+     *
+     * @ORM\Column(type="string", length=30, nullable=false)
+     */
+    protected $recipient;
+
+    /**
+     * The message itself
+     *
+     * @var string $message
+     *
+     * @ORM\Column(type="text", nullable=false)
+     */
+    protected $message;
+
+    /**
+     * Password locations. This must be an array of arrays containing the
+     * password's location and length
+     *
+     * @var array $passwordLocations
+     *
+     * @ORM\Column(type="array", name="password_locations", nullable=true)
+     */
+    protected $passwordLocations;
+
+    /**
+     * True if the message is already sent
+     *
+     * @var boolean $sent
+     *
+     * @ORM\Column(type="boolean", nullable=false)
+     */
+    protected $sent;
+}
+