The "Send test email" option doesn't work well

The "Send test email" button allows a user to send a sample reminder to him/her self right now. It should demonstrate what the reminder will normally look like.

Unfortunately, the token expansion in the email is a bit off. In particular, the expansion of "next-date..." gets the next date completely wrong. Basically, the problem is that the token expansion expects "next" in the reminder object to be set, to tell when the reminder is supposed to fire. In this special test case, next isn't set. It ought to be set to "now" in utc.