Announcement pop-up for updates

A popup/modal to tell what's new in an update

Revamped keyboard navigation, tabs can be removed by 'delete' or 'backspace' key

Earlier it was a custom scroll method to highlight a active or selected tab in the list, now it is done using the 'tabindex' and 'focus' properties of HTML and javascript. Anoother important change is that tabs an be removed by 'delete' and 'backspace' keys