By James Pomfret and Terril Yue Jones HONG KONG/BEIJING (Reuters) - Tens of thousands of protesters massed in a rainsoaked Hong Kong park on Tuesday at a candlelight vigil to urge China to respect human rights on the 24th anniversary of the 1989 crackdown on pro-democracy demonstrators in Beijing's Tiananmen Square. In China, most mention of the anniversary was censored from the Internet. ...