Q&A: What's next after Brexit?

Britons have voted to leave the European Union, their concerns about immigration and what some saw as the ever-increasing power of the 28-member bloc trumping the attraction of being part of a single market of more than 500 million people and a European project forged from the ashes of World War II.Here's a look at what happens next:WHAT HAPPENS FRIDAY?Prime Minister David Cameron, head of the ruling Conservative Party, announced he would step down by October. Speaking to reporters outside his D