“Jitters” is the hilarious “backstage” comedy about a series of disasters that befall a theater company trying to open a new play. An hysterical playwright, a diva-ish leading lady, a leading man with an easily bruised ego, insecure supporting actors, a sarcastic stage manager, a sexy seamstress, a faulty bathroom door, and a director trying to hold it all together, add to the mayhem in this funny and sophisticated comedy about opening night jitters.