Group notifications should have the group name in title

Hi,

Recently I've been getting a lot of group notifications from this group and others on this site. I would have preferred that all these messages should be distinguished by their title (mail subject line) - so it's easier to understand from which group exactly the message is coming from.

BTW, great 1.5 release, I'm so excited, although I have to throw away many of my plugins as the functionality is built in - well done!

Guy