Remove TODOs from code.

Fixes #57

app/model.py

@@ -1,5 +1,6 @@
 #!/usr/bin/python3
 
+import os.path
 import sqlalchemy
 
 from datetime import datetime
@@ -500,8 +501,7 @@ class Tracks(Base):
         DEBUG(f"Tracks.get_track_from_filename({filename=})")
         try:
             track = session.query(Tracks).filter(Tracks.path.ilike(
-                # TODO: filename separator is hardcoded here
-                f'%/{filename}')).one()
+                f'%{os.path.sep}{filename}')).one()
             return track
         except (NoResultFound, MultipleResultsFound):
             return None

app/musicmuster.py

@@ -132,7 +132,9 @@ class Window(QMainWindow, Ui_MainWindow):
         if self.music.playing():
             DEBUG("closeEvent() ignored as music is playing")
             event.ignore()
-            # TODO notify user
+            helpers.show_warning(
+                "Track playing",
+                "Can't close application while track is playing")
         else:
             DEBUG("closeEvent() accepted")
 
@@ -516,12 +518,6 @@ class Window(QMainWindow, Ui_MainWindow):
                 silence_at - self.current_track.fade_at
             ))
 
-    def play_previous(self):
-        "Resume playing last track"
-
-        # TODO
-        pass
-
     def search_database(self):
         with Session() as session:
             dlg = DbDialog(self, session)