[IDEA] Update Hint

[BackinBlack]

Even though major updates mean a new image download rather than in place update, I too think there is merit in a notification.
It can be seen from the queries in the forum pages that not all users regularly "check in" to MoOdeaudio.org or even the forum to check on updates.
Many, if not most, software apps advise the user if an update is available, so why not MoOde?
MoOde is, after all, the leading Pi music software. ??