Even amongst the glitz and glitter of the Cannes Film festival, the AmFar gala is very special, the most glamorous occasion of them all. The annual gala that is held by the Foundation for Aids Research has become a part of the Cannes Calendar, and, for fans of gorgeous frocks being worn by the cream of Hollywood and the world’s top models, this is total candy for the eyes. This year all eyes were on Katy Perry. Now, I am not a fan of Katy’s style in general, can never understand how a woman so pretty can get it so wrong on so many occasions. But in a dramatic red…