EXCLUSIVE: Gabin , set to premiere Thursday in Cannes , tells a classic coming of age story, a boy growing up in Northern France who must choose whether to follow a path prescribed by his family or strike out on his own. The documentary directed by Maxence Voiseux bows in the Directors’ Fortnight sidebar, alongside fictional titles including Butterfly Jam , Atonement , and Clarissa . We have your first look at Voiseux’s film in the trailer above. Gabin , shot over a period of 10 years, follows Gabin Jourdel from boyhood through adolescence. He’s the youngest of the Jourdel children and, as a lover of animals, perhaps not well disposed to become a butcher like his father.…