Happy Thanksgiving, Washington. The streets are quiet this morning in the capital; one cab driver remarked to this writer that it was his favorite day to drive in the city — no traffic, no tourists, and everyone he picks up tends to be cheery and a big tipper. The forecast in D.C. today is calling for an unseasonably warm high of 72 degrees, with a solid chance of afternoon showers and gastrointestinal distress. What’s the…