Add 'Bounced' status to subscribers [MAILPOET-684]

Fix SubscriberTest->testItHasGroupFilter() making only one of four assertions due to lack of data.
Fix a small issue with Import. Unexpected values for the status field were converted to 'unconfirmed' rather than 'subscribed' due to non-strict comparison in in_array(). This hindered 'bounced' status import as well.

assets/js/src/segments/list.jsx

@@ -28,6 +28,10 @@ var columns = [
     name: 'unsubscribed',
     label: MailPoet.I18n.t('unsubscribed')
   },
+  {
+    name: 'bounced',
+    label: MailPoet.I18n.t('bounced')
+  },
   {
     name: 'created_at',
     label: MailPoet.I18n.t('createdOn'),
@@ -192,6 +196,7 @@ const SegmentList = React.createClass({
     const subscribed = ~~(segment.subscribers_count.subscribed || 0);
     const unconfirmed = ~~(segment.subscribers_count.unconfirmed || 0);
     const unsubscribed = ~~(segment.subscribers_count.unsubscribed || 0);
+    const bounced = ~~(segment.subscribers_count.bounced || 0);
 
     let segment_name;
 
@@ -229,6 +234,9 @@ const SegmentList = React.createClass({
         <td className="column-date" data-colname={ MailPoet.I18n.t('unsubscribed') }>
           <abbr>{ unsubscribed.toLocaleString() }</abbr>
         </td>
+        <td className="column-date" data-colname={ MailPoet.I18n.t('bounced') }>
+          <abbr>{ bounced.toLocaleString() }</abbr>
+        </td>
         <td className="column-date" data-colname={ MailPoet.I18n.t('createdOn') }>
           <abbr>{ MailPoet.Date.format(segment.created_at) }</abbr>
         </td>

assets/js/src/subscribers/form.jsx

@@ -45,7 +45,8 @@ define(
         values: {
           'subscribed': MailPoet.I18n.t('subscribed'),
           'unconfirmed': MailPoet.I18n.t('unconfirmed'),
-          'unsubscribed': MailPoet.I18n.t('unsubscribed')
+          'unsubscribed': MailPoet.I18n.t('unsubscribed'),
+          'bounced': MailPoet.I18n.t('bounced')
         },
         filter: function(subscriber, value) {
           if (~~(subscriber.wp_user_id) > 0 && value === 'unconfirmed') {

assets/js/src/subscribers/list.jsx

@@ -255,6 +255,10 @@ const SubscriberList = React.createClass({
       case 'unsubscribed':
         status = MailPoet.I18n.t('unsubscribed');
       break;
+      
+      case 'bounced':
+        status = MailPoet.I18n.t('bounced');
+      break;
     }
 
     let segments = false;