The MitUser model caused a constant series of little problems for
users with mit.edu email addresses trying to sign up for different
Zulip servers.
The new implementation just uses conditionals on the realm object when
selecting the confirmation template to use.
Activation emails were using django's sites framework which always has
the domain set to zulip.com.
(imported from commit b81eae96e1a75b64dd93970760b869f3271ce88c)
django.utils.timezone.now returns an aware datetime object because USE_TZ =
True.
Fixes#80.
(imported from commit c60f491fe00a98626ecced94fc3ea1f71f939a38)
I am pretty sure there's no point to using a hash at all. But until I hear
back from the author, let's at least make sure we put as much entropy into the
hash as we expect to get out of it.
(imported from commit 51a231adeab014cc1af8cb67e89baf06e0a1f593)