Save playlist after moving tracks to another list

Fixes: #38

app/playlists.py

@@ -382,6 +382,9 @@ class PlaylistTab(QTableWidget):
         for row in sorted(rows, reverse=True):
             self.removeRow(row)
 
+        with Session() as session:
+            self._save_playlist(session)
+
         self._repaint()
 
     def play_started(self):

musicmuster.desktop

@@ -0,0 +1,24 @@
+[Desktop Entry]
+
+Type=Application
+
+# The version of the desktop entry specification to which this file complies
+Version=1.0
+
+# The name of the application
+Name=MusicMuster
+
+# A comment which can/will be used as a tooltip
+Comment=Music play for internet radio
+
+# The path to the folder in which the executable is run
+Path=/usr/local/bin
+
+# The executable of the application, possibly with arguments.
+Exec=musicmuster
+
+# Describes whether this application needs to be run in a terminal or not
+Terminal=false
+
+# Describes the categories in which this entry should be shown
+Categories=AudioVideo;Audio;