The huge birdcage at the entrance - 8 feet high and large enough to hold about six standing people and looks like a medieval torture chamber. One sassy parrot greets visitors in several languages, his less gregarious cage-mates just do the parrot thing. That's the first thing you notice at Jak's, a rustic restaurant down by the marina at Playa Concorde. It's in an adobe colored building just at the water's edge, about 20'x35' with a shed-type patio alongside, 100 yards from the marina and near the dinghy dock...