HUNDREDS of protesters, many of them Russian emigres, gathered in cities across Europe and beyond to express their outrage over the death of Kremlin critic Alexei Navalny. Often gathering outside Russian embassies, they chanted slogans critical of Russian President Vladimir Putin, whom they blamed for the activist's death, holding up signs calling him a "killer" and demanding accountability. Putin's most formidable domestic opponent, Navalny fell unconscious and died on Friday after a walk at the Arctic penal colony where he was serving a three-decade sentence, prison authorities said. In Berlin, a crowd of 500 to 600 people, according to police estimates,…