Barring any unwelcome intrusions, sometime in 2009 the U.S. Mint could roll out an official D.C. quarter bearing the city’s slogan, “Taxation Without Representation,” to great fanfare. But considering that unwelcome intrusions are part and parcel of living in the District, we’re not yet holding our breath. Yesterday Mayor Adrian Fenty formally submitted the District’s three proposals for its own quarter to Secretary of the Treasury Henry Paulson, arguing in a memo that the voting…