New feature: Email Digests

I noticed a number of users who register but aren't high-volume posters are checking the job listings, so SJ now provides email digests of the latest job listings and top posts in the journalism forums.

- If you're actively job hunting, you can turn on "email subscription" which send an email once a day with the latest job posts. This email requires you to opt-in, and you can subscribe/unsubscribe using the link at the bottom of every page that says "Email Subscription"

- If you've logged in within the past 30 days, you'll get the weekly digest. The first one will go out later this week. This email is opt-out, and you can subscribe/unsubscribe using the link at the bottom of every page that says "Weekly Digest".

- If you haven't logged in within the past 45 days, you'll get the monthly digest. I wish I could set it to send once a quarter, but monthly is the longest time period Xenforo supports. The first one went out last night, and after it sent, I realized I'd accidentally misconfigured it to send a small number of folks two copies. That bug should be fixed now. This email is opt-out and you can subscribe/unsubscribe from the monthly digest using the "Receive Site Mailings" setting.

The chit-chat and off-topic forums are excluded from all these emails, so hopefully the signal-to-noise ratio is decently high.