A Hollywood celebrity who has been an Austin mainstay for years is selling his house overlooking Lake Austin. Dennis Quaid recently listed his nearly 5,000-square-foot home in the gated Marina Club development adjacent to the Austin Country Club. Quaid’s younger brother Buddy Quaid and Eric Copper, both with Austin Portfolio Real Estate, the luxury division of Keller Williams Realty, have the co-listing. The price is $3.5 million. Quaid has owned the property for four to five years, Copper…