[Bug 29213] Add a separator between the menus and gnome-app-install

[Sebastian Heinlein]

Public bug report changed:
https://launchpad.net/malone/bugs/29213

Comment:
This should be a better solution. Other files get merged before the
separator:

   <Include>
    <Filename>gnome-app-install.desktop</Filename>
   </Include>

   <!--  Separator between menus and gnome-app-install -->
   <Layout>
     <Merge type="menus"/>
     <Merge type="files"/>
     <Separator/>
     <Filename>gnome-app-install.desktop</Filename>
   </Layout>