K Street. The very mention of this once-thriving street-turned-derelict-pedestrian mall sends people who’ve watched downtown’s progress, or lack thereof, into fits. Everyone has an opinion, an accusation, a conspiracy theory or a pet peeve about it. And everyone has got a cure-all, that one big project that will change EVERYTHING. Tuesday night, the City Council will meet to vote on which of the two teams of developers proposing projects for the 700 and 800 blocks of K Street should be given an exclusive right to negotiate. This is a big deal, with tens of millions of dollars in one case, or, in the other case, hundreds of millions of dollars involved. More important, it is a test of wh