Microsoft Corp (MSFT.O) and Google Inc (GOOGL.O) have agreed to bury all patent infringement litigation against each other, the companies announced on Wednesday, settling 18 cases in the United States and Germany. In another sign of the winding down of the global smartphone wars, the companies said the deal puts an end to court fights involving a variety of technologies, including mobile phones, wifi, and patents used in Microsoft’s Xbox game consoles and other Windows products.