By Jethro Nededog LOS ANGELES (TheWrap.com) – The cast of “Outlander” continues to grow with the addition of Duncan LaCroix in the role of Murtagh Fitzgibbons Fraser. Author Diana Gabaldon, whose bestselling books provide the basis of the series, broke the casting news on Twitter. Starz and Sony Pictures Television later confirmed the casting. “I’m Very Pleased Indeed to announce that Murtagh will be played by Duncan Lacroix!” she wrote. …