Add ability to hide played items in a feed

- Use components from the new Groupie list library for displaying the
feed list.

app/src/main/res/menu/menu_feed_fragment.xml

@@ -2,9 +2,17 @@
 <menu xmlns:android="http://schemas.android.com/apk/res/android"
     xmlns:app="http://schemas.android.com/apk/res-auto">
 
+    <item
+        android:id="@+id/menu_item_feed_toggle_played_items"
+        android:checkable="true"
+        android:checked="true"
+        android:icon="@drawable/ic_visibility_on"
+        android:title="@string/feed_toggle_show_played_items"
+        app:showAsAction="ifRoom" />
+
     <item
         android:id="@+id/menu_item_feed_help"
         android:icon="@drawable/ic_help"
         android:title="@string/help"
-        app:showAsAction="always" />
+        app:showAsAction="never" />
 </menu>