Women are in firm control of the kingdom in Broadway’s Cort Theatre, where a new revival of “King Lear,” starring Glenda Jackson in the title role, opened Thursday. Jackson’s Lear is, naturally, the production’s dominant, galvanizing force: It’s a performance as fiery and ferocious as it is authoritative. But she is surrounded by a cast of fellow female performers — including Jayne Houdyshell as a marvelous Earl of Gloucester, in another gender-switched performance, and Ruth Wilson, doubling as Cordelia and the Fool — who often outshine their male counterparts in director Sam Gold’s largely compelling if uneven production. Gold, who…