Please don't add 01 to basename of iso if there is only one track

[alexmyczko]

https://bugs.debian.org/cgi-bin/bugreport.cgi?bug=271285

[twojstaryzdomu]

I've added a few options, including the ability to suppress adding the track number altogether and use the original filename minus the source extension plus the output extension with the options -t ''. See PR #15.