Main::PSGI: refactor status rendering into _format_status_html_destructive() method. busybird.level is now 0 by default.
timeline.tt, busybird.css: little fixes about view.
timeline.js: properly call setCursor() at start up and on click to status elements.
timeline.js: StatusContainer: .bb-status-new-label elements are removed just before loadUnackedStatuses().
timeline.js: StatusContainer: removabl of .bb-status-new-label elements are now delayed until the new unacked statuses are successfully loaded. That way, the labels persist if it fails to load the unacked statuses.