[patch] improvements for media-control

[Michal Hruby]

I did some improvements to media-control applet.

The most notable are changes to Rhythmbox applet, where the album art fetching is now better (supports for example Folder.jpg album art, reported directly from Rhythmbox) plus the applet listens for signals from the players (via dbus - currently only working with rhythmbox), which means that the applet window will update title+albumart even if it's open and player starts playing different song.

Another improvement is that if there isn't any player running, the applet will show a couple of buttons instead of the standard controls, which start players present on your system, once the player is started and applet dialog is opened again, the usual interface is presented (with 3 control buttons).

Possible future enhancements:
- listen for dbus's NameOwnerChanged signal, which will enable connecting to player's dbus interface as soon as it's started (currently applet must be clicked to look for running players and eventually connect to them)

[Mark Lee (malept)]

Reassigning to 0.4.0, as 0.2.8 will not contain any enhancements.

[IM.tehk (im-tehk)]

The patch looks wonderful. Feel free to commit the changes and any future ones to awnmediaplayers involving signals and the NameOwnerChanged signal.

[Michal Hruby (mhr3)]

First part of the patch is committed in awn-extras trunk R771, more to come - as mentioned NameOwnerChanged signal should be handled + support for other players' signals should be added.

[Michal Hruby (mhr3)]

Handling of NameOwnerChanged signal was committed in awn-extras trunk R784.

The only thing missing now is support for more players which do emit dbus signals.