Apply role to "new users"

[robstolarz]

Although we have a "Guest" role that prevents users from seeing the content of the server if they don't agree to abide by its rules, we don't have a similar role that is applied to users who have not been on the server for very long.

Reasons to apply such a role would be to deny access to certain channels until a user is considered "ready" for them, like some of the Discussion channels on Programming that tend to attract unwanted attention by new users.

It would be nice if there were configurable thresholds for # of messages as well.

edit: Is this a good candidate for StatBot integration? Such an integration would probably prevent extra work.