Last week we reported that D.C. Mayor Anthony Williams takes in $152,000 in compensation, a salary some viewed as excessive and others as not excessive enough. But if this is how much we currently judge the city’s chief executive to be worth, what would we pay, let’s say, the chief librarian? A lot more, as news has it. The Common Denominator reported on Friday that the D.C. Board of Library Trustees decided to hire Ginnie…