sagenb.org back up

[Jason Grout]

You may have noticed that sagenb.org and related servers are back up.
There are several changes:

1. New accounts must use openid. Existing accounts will still be able
to log in.

2. There is a quota of 250M. If your account exceeds 250M in data, it
will be changed to "read-only". You'll be able to download worksheets,
delete worksheets, and delete data files. When your account goes below
250M, it will be re-enabled.

Thanks,

Jason