THECHAT &lt;em&gt;  After W.A.S.P. rocker and Yankees fan Blackie Lawless sneered at Red Sox fans in this space, we figured it was time to find a hard core Red Sox rooter.  And who better than Ken Casey of the Dropkick Murphys, the punk/rock/Irish folk band whose "Tessie" -- a remake of an early 20th century Boston anthem, with backup vocals from Johnny Damon, Bronson Arroyo and Lenny DiNardo -- has become de rigueur listening in the Fens? The Murphys are headlining today's scheduled playoff rally at Fenway Park.&lt;/em&gt;