PORTLAND, Maine -- Twenty-seven paintings by three generations of Wyeths have been donated to Maine's Farnsworth Art Museum, thanks to the late Betsy Wyeth.The Rockland museum, which plans to display the paintings in a major exhibition beginning May 15, did not disclose the value of the gifts, the Portland Press Herald reported Thursday.The gift includes “Room after Room” and “Geraniums," a pair of watercolors painted by Andrew Wyeth at the Olson House in nearby Cushing; “Islander," one of Jamie