Created stats for users (number of users and list of newest users). Better separated the forums, who's online, and user stats. Use a Celery task to execute the new user stats processing. This addresses #194 and #238.

#downloads-add td {
    padding-bottom: 5px;
}

#downloads-add fieldset {
    margin: 1em 0 1em;
    padding: 0.5em;
}