In one of his last interviews before leaving Congress, Rep. Barney Frank gave a preview of the kind of no-holds-barred pundit he will be as he moves on to write books and become a TV commentator. The retiring 16-term openly gay Massachusetts Democrat called for the legalization of prostitution, cheered Washington State and Colorado for legalizing marijuana, labeled Justice Antonin Scalia “an unreconstructed bigot,” criticized those who took Prop 8 to the Supreme Court, defended the free speech of the infamous Westboro Baptist Church, and heralded the arrival of Congress’s first “gaysian” -- the election of Mark Takano, an openly gay Asian-American from California to the House