New groups feature - publicize your group jam

We've added a few feature to groups.

You can now optionally have your group jam sessions appear on the public maps. When you flag a group to show on the main maps and calendars only the date, title and city/region/country will appear to people who are not members of your group.

This allows you to let the world know that you have a jam session, but won't let anybody but the members of your group see the full details.

Let us know what you think of this latest addition to the site.