Fullbackup

Hi mate,

thanks for sharing you script, I found it very useful. I added some code to suit my own needs and I'm sharing it with you.

This branch adds support for full tumblr backups with an option to limit the maximum number of downloaded photos, and removes a few bugs along the way. I'm *not* a Ruby developer, so I offer my apologies for any ugliness in the code. I just tested the script now on a tumblr blog with roughly 2.000 photos and it completed successfully.

Cheers, mate!
Igor