Added default option to mainloop select

[infEreb]

With this we no longer have to wait for any update events for View to update, this would be very helpful for creating dynamic widgets and generally more convenient than cumbersome userEvents

This doesn't break the old logic and keeps the need for userEvents for some cases I would be very grateful if you would accept

[infEreb]

If you favor the old logic, how about at least a bool flag (e.g. Dynamic) that would be in Gui and used in the default select

default:
    if !g.Dynamic {
        continue
    }