Lua SD: implement the descriptor() function in scripts

share/lua/sd/fmc.lua

---SD_Description=Free Music Charts
 --[[
  $Id$
 
@@ -22,6 +21,10 @@
 --]]
 require "simplexml"
 
+function descriptor()
+    return { title="Free Music Charts" }
+end
+
 function main()
     local tree = simplexml.parse_url("http://www.archive.org/download/freemusiccharts.songs/fmc.xml")
     for _, show_node in ipairs( tree.children ) do

share/lua/sd/freebox.lua

---SD_Description=Freebox TV
 --[[
  $Id$
 
@@ -21,6 +20,10 @@
  Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston MA 02110-1301, USA.
 --]]
 
+function descriptor()
+    return { title="Freebox TV" }
+end
+
 function main()
     local fd = vlc.stream( "http://mafreebox.freebox.fr/freeboxtv/playlist.m3u" )
     local line=  fd:readline()

share/lua/sd/frenchtv.lua

---SD_Description=French TV
 --[[
  $Id$
 
@@ -21,6 +20,10 @@
  Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston MA 02110-1301, USA.
 --]]
 
+function descriptor()
+    return { title="French TV" }
+end
+
 function main()
     node = vlc.sd.add_node( {title="Canal +"} )
     node:add_subitem( {title="Le SAV des émissions ",url="http://www.canalplus.fr/index.php?pid=1782",options={"http-forward-cookies"}} )