Lane Turner/The Boston Globe via Getty Images(WASHINGTON) -- A dispute over a Boston flagpole, the Christian flag and the First Amendment is testing the limits of free speech on government property. The U.S. Supreme Court on Tuesday will hear arguments over whether the city of Boston engaged in unlawful discrimination and censorship when it denied the request of a local civic organization to fly the Christian flag on a flagpole outside City Hall. Designed in the late 1880s, the white banner with red Latin cross has been adopted by many American Protestant communities as a nondenominational sym...