gui/audioplayer.cpp: disable screen save for dline/ibox;

always load metadata when adding files to play list;
cleanup code

src/gui/audioplayer.h

@@ -151,6 +151,7 @@ class CAudioPlayerGui : public CMenuTarget
 	void paintHead();
 	void paintFoot();
 	void paintInfo();
+	void paintCover();
 	void paintLCD();
 	void hide();