Documentarian Jeff Krulik’s previous shorts (including, but not limited to “Heavy Metal Parking Lot”, “Neil Diamond Parking Lot”, “Harry Potter Parking Lot” and “King Of Porn”) are achingly funny snapshots of real-life-America that somehow manage not to totally sneer at those being profiled.  That’s your job!   “Heavy Metal Picnic” premieres tonight and for the first time in recent memory, I can truly say I’d rather be in Silver Springs, MD.