add app version output to version.txt

+ refactor main entry point
+ add debug logging in image extraction

swingmusic/__main__.py

@@ -108,10 +108,6 @@ def run(*args, **kwargs):
     start_swingmusic(kwargs["host"], kwargs["port"])
 
 
-def main():
-    multiprocessing.freeze_support()
-    multiprocessing.set_start_method("fork")
-    run()
-
 if __name__ == "__main__":
-    main()
+    multiprocessing.freeze_support()
+    run()