Reorganize classes to increase reusability - everything should work except drag-and-drop over the right panel
Drag-and-drop over right panel is working now
Use ToUpper() when searching for song title index (so lowercase filenames don't cause problems)
Display error message if mu_menumain doesn't exist and they try to update it
Add ExportMSBin method
Transfer UpdateMenumain code to MainForm
Update version number
Move SongNameBar and SongPanel to library