Don't download same episode again

[pejg12]

Since I like having the episode title in the filename, and SVT are terribly bad with adding such titles, I rename most of my files after they have been downloaded. When running the download script later, to download more recent episodes, I end up with the same episode using a different filename.

The best solution would be to fetch some sort of checksum from SVT servers to prevent the initial download.

A bad workaround would be to download the file, convert it as usual, and then compare the resulting file with the checksums of everything else in the directory. If there's a match, delete the new file to keep the old filename instead.