Resume partial/aborted downloads about bandcampdownloader

[Otiel]

I've released a new version with @ajsnyde changes.

[ajsnyde]

See ajsnyde@72c442f

Added functionality that checks for existing files before downloading. The filesizes are then compared, with some wiggle room to account for the addition of album covers and metadata. The default of AllowableFileSizeDifference is .05, but can be set to 0.00 to disable the functionality entirely, or 1.00 to simply check for filename existence. Like other changes I've made, you'll have to save settings to a file and then manually change values.

[Otiel]

That's a good idea. I'll have to think of ways on how to check if an existing file is complete without being forced to download it once more.

[servix]

Great! Let me know if you need to perform some testing...

[ajsnyde]

@Otiel I can take this task out too, if needed.

[Otiel]

@ajsnyde Please do if you want!