libraries get associated with a library_block table (IP ranges)
moved superlogin here
IP stuff mostly copied from
https://github.com/benliles/django-ipauth/blob/master/ipauth/models.py
The model is that you need to be in an allowed IP range to "join" a
library. Once you've joined, you can use your login from anywhere. to
use that library.
Asign IP ranges in admin
439169a1ab