Soak the baccala in cold water for 24 hours to re-hydrate, changing the water 3 times to remove the salt. Drain and rinse under cold water and put into a large pot. Add the milk and enough water to cover by 1-inch. Cook uncovered over medium heat for 45 minutes. Drain and set aside to cool. When fish is cool enough to handle, shred the fish into a bowl, taking care to get all the bones out. Add onion, parsley, and tomatoes. In a separate bowl, whisk together olive oil, vinegar, lime juice, and salt and pepper. Add the dressing to the cod salad, toss and serve.