Clean up temporary files when there is error / crash

[https://www.google.com/accounts/o8/id?id=aitoawlc7d5deftwwl4cwbnpgbr1zm1h94hxiby]

In my experience, it is common to have morituri crash (either with Python error messages, or what seems to be internal error messages) when the disc is scratched or dirty.

When that happens, apparently morituri leaves .wav and .flac temporary files in /tmp. It would be nice to implement a way to erase those files before or after (that is, next time morituri is executed) a crash. (Those large files can quickly accumulate and fill up the disk.)

[https://thomasvs.myopenid.com/]

I agree, this would be nice to do. Probably before exiting though; you wouldn't want more than one rip process to delete other tmp files.