It is a situation devoutly to be wished – to be saturated with artistic excellence everywhere you look for over two hours.  “Just In Time” – recently opened at Circle In The Square will do that to you.  From the moment you enter the theatre, you are surrounded by glowing blue lighting, drapes, and a cocktail table scattered across the orchestra section.  This is Bobby Darin’s world, and welcome to it.  Your host for the show is the thrilling Jonathan Groff, who makes no bones about NOT being Bobby Darin.  He is there to tell the story.  Well, SING the story might be more accurate.