By RICARDO CASTILLO     Both houses of the Mexican Congress are about to embark on a rewriting of the Ley Federal del Trabajo (Federal Labor Law, or LFT). The LFT debate is expected to be multifaceted and particularly interesting, mainly because the administration of the current Mexican president, Andrés Manuel López Obrador (AMLO), will undoubtedly favor the exploited and beleaguered Mexican working class.