Assemblyman Tom Ammiano's press conference this morning announcing his marijuana-legalization bill started punctually and stayed relentlessly on-point -- thereby denying a barb to every journalist present.Ammiano and the assembled speakers at San Francisco's State Building also spoke calmly and methodically, at one point being drowned out by a floor-waxer. The famously funny lawmaker reined himself in, presenting "The Marijuana Control, regulation and education act (AB 390)" as a simple matter o