AutoPanel: new cfg option 'autopanel_refresh_interval'

New option autopanel_refresh_interval can be specified within AutoPanel
configs or within the returned compontent to set 'AutoRefresh' on the
Ext Updater object. When specified, the panel will reload itself at
least every that number of seconds. Manual reloads restart the timer.
This is useful in places where content may change frequently and you
want shown to users who already have the interface loaded and without
user intervention (clicking reload)