In New York state, contrary to gubernatorial candidate Jimmy McMillan, the rent is not too damn high. It's actually too damn low in most places -- and that fact reflects the state's true problems. McMillan created a sensation at this week's gubernatorial debate with his handlebar mustache and his incessant repetition of his slogan about rents being too high. Although McMillan is evasive about his own rent (The Post reported yesterday that he pays $800 a month for a Brooklyn one-bedroom), news accounts and typical "voter in the street" interviews suggest many people approve of McMillan's gripes that rents are...