gtk-play: use volume-changed signal from player to update the volume slider.
gtk-play: use volume-changed signal from player to update the volume slider.

JimmyOhn/gst-player,sdroege/gst-player,shakin/gst-player,guiseco/gst-player,sdroege/gst-player,amorenoc/gst-player,amorenoc/gst-player,JimmyOhn/gst-player,codomania/gst-player,shakin/gst-player,codomania/gst-player,justinjoy/gst-player,codomania/gst-player,shakin/gst-player,JimmyOhn/gst-player,justinjoy/gst-player,sdroege/gst-player,amorenoc/gst-player,JimmyOhn/gst-player,justinjoy/gst-player,sdroege/gst-player,jabiers/gst-player,guiseco/gst-player,JimmyOhn/gst-player,sdroege/gst-player,guiseco/gst-player,amorenoc/gst-player,codomania/gst-player,jabiers/gst-player,codomania/gst-player,jabiers/gst-player,amorenoc/gst-player