Un-used hs text output & delete all

1. Added option in properties file to output unused.txt (contains all unused hs), text file will be same location where you put hitsound detective.jar
2. If you have unused hs, you will get a new popup to ask you if you want delete all unused hs samples in song folder.
3. Fix bug where it shows wrong format hs (ogg) , ogg is now supported in osu!