TWO DECADES ago, Kelsey Grammer and Martin Lawrence were playing very different broadcast personalities on very different hit shows. Tonight, the stars of "Frasier" and "Martin" join forces in a new FX sitcom, "Partners," as very different Chicago lawyers. "We sat down in a room about two years ago and just fell in love," Grammer said of the otherwise unromantic-sounding process that led them back to TV. "Partners," which shares a name with at least two previous sitcoms, is the latest cable comedy to be sold on the "10/90" model, in which a network orders 10 episodes, whose ratings performance may trigger an order for 90 more, as it did with Charlie Sheen's "Anger Management." Read more at http://www.philly.com/philly/entert...with_Martin_Lawrence.html#3Qr3m555vMRESeRJ.99