A surge in iPhone 6 and 6 Plus sales led to a record-setting fiscal second quarter for Apple Inc., while the company also announced it will be returning more cash to its shareholders. Apple revenue for the three-month period topped the nation of Croatia's entire gross domestic product for the full year 2013, according to World Bank data. Shares rose 1.3 percent Monday in after-hours trading, following the earnings report. The Cupertino company said its board has authorized a more than 50 percent…