D.R. Horton's (DHI) quarterly earnings, out early Tuesday, trounced analyst estimates. Horton was the first of five builders slated to announce results this week, along with No. 1 paint and coatings maker Sherwin-Williams (SHW). Ryland (RYL) is on tap to report after the market closes. The latest S&P Case Shiller composite index of home prices in 20 metropolitan areas also came out early Tuesday. As expected, single-family home prices rose a