Enhanced reminding for dues-lapsed members

[carmiendo]

About once a year or so, it's the job of the membership coordinator to review members whose dues have lapsed for more than a couple of months and email them to ask them to re-set up their dues or go on scholarship. If a member doesn't pay dues but also isn't on scholarship for more than a few months, after plenty of warnings the membership coordinator will assume they don't want to be a member anymore and end their membership.

We already send an email the first time a member's dues payment fails. This is a feature request to flesh out that reminder process to continue to remind them for a certain amount of time until we are ready to assume that they've silently cancelled their membership, and then cancel it for them.

This would save the membership coordinator some stressful work, and hopefully keep people whose dues are lapsing by accident up to date more promptly than doing this manually would.