Las Vegas casino developer Steve Wynn is escalating his battle with Boston officials, filing a libel lawsuit this week against an unidentified casino foe and issuing a scathing critique of the treatment his company has received since it arrived in the Boston area with plans to build in Everett. “No individual or company who presents themselves honestly in the Commonwealth of Massachusetts, by any measure of fair play, should be subjected to the defamatory political abuse that we have experienced, and it is our intention to finally deal with it,” Wynn said in a statement to the Globe.