So it transpires that the city Depart ment of Investigation has been on to reports of a snow-removal slow down all week. Go to it, folks. People could have died because of the mini-mutiny -- and those responsible have much for which to answer. The Post reported yesterday that sanitation employees purposely delayed plowing streets during and after the Christmas weekend blizzard. It now seems that there was an effort to target certain politically connected neighborhoods -- like Borough Park in Brookyn and Middle Village in Queens. Why? Because hard times are on the city, austerity looms for everyone --...