Caesars Entertainment and 11 other Atlantic City casinos have begun the process of getting online gambling licenses ahead of a Sunday deadline set by New Jersey regulators. They’re part of a rush to get in on the ground floor as online gambling gets ready to go mainstream nationwide. New Jersey will in November be the third state to launch statewide online poker and other gaming, after Nevada and Delaware. The new gaming outlet became possible when the federal government did an about-face in December 2011. After adamantly opposing online gambling for years, the government said states could issue licenses, but…