“What to do when you’ve been accused, by various publications and Web sites, of all manner of misbehavior: money laundering, blowing $5 million on your daughter’s wedding and massacring mustangs to use their skins for upholstery?” Janna Bullock, “the glamorous Russian-born real estate developer and art scene fixture,” is trying to reclaim some respect with an exhibition that take[s] on nothing less than the Russian power elite, from Vladimir V. Putin to Mikhail S. Gorbachev.”