MELEKHOVO, Russia (Reuters) -Jailed Russian opposition politician Alexei Navalny was sentenced on Friday to an additional 19 years in prison after being found guilty on a series of new charges, Navalny's supporters said on social media. In a video feed from a court hearing at a penal colony east of Moscow, Navalny could be seen wearing a black prison uniform and standing with his arms folded as he listened to the verdicts. Navalny, the most prominent opponent of President Vladimir Putin, is already serving 11-1/2 years in the penal colony on charges including fraud that he says were tru...