Macbeth, Queensland Theatre Company, The Playhouse, Brisbane, April 9. Cock, Melbourne Theatre Company and La Boite, The Roundhouse Theatre, Brisbane, April 9. QUEENSLAND Theatre Company’s Macbeth isn’t set in a boardroom, or in Nazi Germany, or in the fiefdom of the Klingons. The unchanging set (Simone Romaniuk, who also designed the costumes) is a thicket…