BUDAPEST, Nov 20 (Reuters) - Hungary's ruling party unveiled billboards vilifying European Commission President Ursula Von der Leyen on Monday, the first time it has made her a personal target in a campaign similar to one against her predecessor that angered Brussels. The billboards, erected overnight to launch a campaign for next June's European parliamentary election, depict Von der Leyen alongside Alex Soros, the son of liberal Hungarian-born financier George Soros, a perennial target of hostility from Orban's Fidesz Party. The slogan reads: "Let's not dance to their tunes". Soros is Jewish and some critics view the central role he...