KABUL (Reuters) - Four people were shot dead and dozens wounded in protests in Afghanistan which flared for a second day on Wednesday in several cities over the burning of copies of the Koran, Islam's holy book, at NATO's main base in the country. The American Embassy said its staff were in "lockdown" and travel had been suspended as thousands of people expressed fury over the burning, a public relations disaster for U.S.-led NATO forces fighting Taliban militants ahead of the withdrawal of foreign combat troops by the end of 2014. The U.S. ...