PepsiCo (PEP) which owns Gatorade is railing against Coke's (KO) recent advertising campaign that claims the popular thirst quencher is "an incomplete sports drink." The spot goes on to tout Coke’s Powerade which contains two ingredients not found in Gatorade - calcium and magnesium. As Pepsi busies itself with planning its retaliation we decided to investigate Coke’s claim and gave…