youtube.lua: add demux=avformat,ffmpeg for options

This should help watching mp4-videos (&fmt=18 and 22 or something like that)
from youtube. ffmpeg for fallback for windows. Not idea about OS X side.

share/lua/playlist/youtube.lua

@@ -38,6 +38,7 @@ function probe()
     if vlc.access ~= "http" then
         return false
     end
+    options = {":demux=avformat,ffmpeg"}
     youtube_site = string.match( string.sub( vlc.path, 1, 8 ), "youtube" )
     if not youtube_site then
         -- FIXME we should be using a builtin list of known youtube websites
@@ -103,10 +104,10 @@ function parse()
             format = ""
         end
         if t then
-            return { { path = base_yt_url .. "get_video?video_id="..video_id.."&t="..t..format; name = name; description = description; artist = artist; arturl = arturl } }
+            return { { path = base_yt_url .. "get_video?video_id="..video_id.."&t="..t..format; name = name; description = description; artist = artist; arturl = arturl; options = options } }
         else
             -- This shouldn't happen ... but keep it as a backup.
-            return { { path = "http://www.youtube.com/v/"..video_id; name = name; description = description; artist = artist; arturl = arturl } }
+            return { { path = "http://www.youtube.com/v/"..video_id; name = name; description = description; artist = artist; arturl = arturl; options=options } }
         end
     else -- This is the flash player's URL
         if string.match( vlc.path, "title=" ) then
@@ -123,8 +124,8 @@ function parse()
         if not string.match( vlc.path, "t=" ) then
             -- This sucks, we're missing "t" which is now mandatory. Let's
             -- try using another url
-            return { { path = "http://www.youtube.com/v/"..video_id; name = name; arturl = arturl } }
+            return { { path = "http://www.youtube.com/v/"..video_id; name = name; arturl = arturl; options=options } }
         end
-        return { { path = "http://www.youtube.com/get_video.php?video_id="..video_id.."&t="..get_url_param( vlc.path, "t" )..format; name = name; arturl = arturl } }
+        return { { path = "http://www.youtube.com/get_video.php?video_id="..video_id.."&t="..get_url_param( vlc.path, "t" )..format; name = name; arturl = arturl; options=options } }
     end
 end