Photo by drewsaunders A creepy new development today in the ongoing federal investigation into allegations of widespread bribery attempts inside the D.C. taxicab industry, courtesy the Post’s Del Quentin Wilber: court documents released today detail how one of the 39 men charged in the bribery ring, Yitbarek Syume, allegedly threatened to murder FBI informant Abdulaziz Kamus when his name surfaced in media reports shortly after the investigation became public.The papers reveal that Yitbarek Syume…