Re-generate thumbnails

[dgrant]

If the photo was updated, it would be nice to re-generate the thumbnails.

if os.path.exists(os.path.join(dest_dir, thumb[0])):
    continue

I'm thinking instead of the above, we could check whether the photo timestamp is newer than the timestamp of the thumbnail? And if so, re-generate it? I could implement this, just want your opinion on whether this would work or makes sense.

[mrchief]

I think this is a great idea!

[tobintax]

Anything happened here? :-)

[Kvanrooyen]

Hey @dgrant, @mrchief and @tobintax I will be trying to keep this project more updated on my fork