Carmen Cusack shines in Encores! revival of its 1995 landmark revival of Irving Berlin’s “Call Me Madam” (1950), originally written as a vehicle for Ethel Merman.  A topical piece of light satirical fare that’s more about comedy and songs than plot, this simple but well-performed production is Encores! at its truest: a concert revival of a classic musical that would not otherwise be seen on stage again.