I’m not remarking on the quality of this new Lifetime movie – just on the casting, which is reason enough to tune in on a slow Sarturday night. Gina Gershon stars as Donatella Versace, the fashion designer who, until now, has been most visibly and famously portrayed by Maya Rudolph on Saturday Night Live. And also featured in this movie, in a supporting role: Raquel Welch. The stars of Showgirls and One Million Years B.C. in the same movie? Here we go…