First steps for folder support.

app/src/main/res/values/strings.xml

@@ -236,4 +236,7 @@
     <string name="folders">Folders</string>
     <string name="saved_playlist_to">Saved playlist to %s.</string>
     <string name="failed_to_save_playlist">Failed to save playlist (%s).</string>
+
+    <!-- TODO: Remove or change this placeholder text -->
+    <string name="hello_blank_fragment">Hello blank fragment</string>
 </resources>

app/src/main/res/values/strings_activity_settings.xml

@@ -5,6 +5,7 @@
         <item>@string/albums</item>
         <item>@string/artists</item>
         <item>@string/playlists</item>
+        <item>@string/folders</item>
     </string-array>
 
     <string-array name="pref_start_page_list_values">
@@ -13,6 +14,7 @@
         <item>1</item>
         <item>2</item>
         <item>3</item>
+        <item>-2</item>
     </string-array>
 
     <string-array name="pref_general_theme_list_titles">