Los Angeles Ballet 2011 Gala Features a Glorious Giselle and a Dream Dinner   Following a performance of “Giselle” at the Los Angeles Ballet’s ”Season 5 Gala Celebration,” artistic director Colleen Neary surprised the audience at the Broad Stage in Santa Monica by naming Allyssa Bross and Christopher Revels as principal dancers, the first dancers so designated in the young ballet company’s history. It was a night of firsts, starting with the May 28 Los Angeles Ballet Gala, the company’s first ever. Aptly christened “A Midsummer’s Night Dream,” the entire evening seemed magical, beginning...