dxSudoku #115 Puzzle Fun #1 X-Wings and Skyscrapers

Here I introduce a new series of videos. This puzzle features a nice constellation of gives, several X-Wings, and one Skyscraper. In solving this puzzle I will be using the Modern Software Approach method I've documented in my videos and my books. Here's the 81 character puzzle string: ....8.....5.9.2.1...1.7.9...2.8.6.7.4.9...5.2.6.2.4.9...5.3.8.....4.7.3.....6....