By Dan Weil The Case-Shiller Home Price Index slid 0.3% in July from June, the largest monthly decline since November 2014. It looks like the tide might be gradually starting to turn for the housing market. The S&P CoreLogic Case-Shiller Home Price Index dipped 0.3% in July from June, the largest monthly decline since November 2014. To be sure, prices soared 15.8% in the 12 months through July, but that’s still a slowdown from 18.1% in the 12 months through June. The 2.3 percentage-point difference is the largest deceleration in the index’ history going back to the 1980s. “Although U.S. housin…