Real-estate magnate Donald Trump frequently touts his wealth on the presidential campaign trail. But a new report essentially accuses the GOP candidate of overstating his net worth by billions of dollars.Bloomberg reporters Caleb Melby and Richard Rubin, citing an analysis by the Bloomberg Billionaires Index, reported Thursday that Trump was actually worth about $2.9 billion.That's more than $7 billion less than Trump has said.In a statement earlier this month, Trump's campaign wrote that the real-estate developer and television personality has seen his net worth rocket upward even in just the past year."Real-estate values in New York City, San Francisco, Miami,...