#157 Go to next directory or previous directory of images

[Sachitha Obeysekara]

I typically view directories of images rather than archives of images so ut would be nice to move to the next directory of images after the last image, or move to the previous directory of images before the first image. Similar to how it works with "next archive" feature. I had a quick look at the code and hacked it to do this, the patch is attached, it would be good it someone could review my patch and make the change properly as I am not familiar with the Comix codebase or Python for that matter.

Thanks,
Sach

[Sachitha Obeysekara]