PHILADELPHIA (AP).- The Barnes Foundation will open a new downtown home for its multibillion-dollar art collection on May 19, officials announced Thursday, even as a judge continued to weigh whether the masterpieces should be moved at all from their current suburban home to Philadelphia. Barnes officials insisted the hotly contested relocation of hundreds of paintings by artists including Renoir, Cezanne, Matisse and Picasso will happen this spring despite a lawsuit challenging the $200 million venture. “I can say proudly, boldly and forcefully we should be opening here on May the 19th, 2012,” foundation President Derek Gillman said at a news conference. The art collected by eccentric pharmaceutical magnate Albert Barnes includes 800 impressionist and post-impressionist masterpieces that he displayed for decades in a limestone gallery in Lower Merion. He meticulously grouped the paintings with antique ironwork, furnit