By RICH GRANT This much, everyone agrees on. At 3 p.m. on the cold, blistery afternoon of Oct. 26, 1881, Wyatt Earp, his two brothers Virgil and Morgan, and Wyatt’s friend John “Doc” Holliday set off down Fremont Street in Tombstone, Arizona. They walked side-by-side. Virgil Earp was the acting town marshal, the other men had been deputized. Each man