Serbia’s populist President Aleksandar Vucic said on Saturday that he would resign his post within weeks, paving the way for early elections following youth-led protests that shook his tight grip on power. Vucic did not specify exactly when he would resign or when an election, either for parliament or for a new president, could be held. He has said in the past that he could leave the post amid speculation that he would try to switch to the formally more powerful position of prime minister of the...