#3 If you save unsaved changes on exit, program doesn't exit

[Austin Bingham]

If you make changes to you deck and "quit" before
saving, you are prompted for whether you'd like to save
your changes. If you click "Yes" for this, the changes
do get saved, but pitacard doesn't exit. If you
subsequently select "Quit" again, it does exit
properly. Likewise, if you select "No" when prompted to
save changes, the changes are not saved and the program
exits normally. This is almost certainly a bug in the
SaveFileManager class.