Boston City Councilor Sam Yoon may not have made it to the second stage of the mayoral election in November, but don't count him out yet. In a historic move, Yoon will be campaigning with Michael Flaherty on an innovative "joint ticket" with Flaherty for Mayor and Yoon for Deputy Mayor.  The "unusual partnership," announced this morning at City Hall by the candidates, is believed to be a first, according to the Boston Globe.