Last year the Belfast Film Festival opened with Deniz Gamze Ergüven’s Mustang, a modern Turkish fairytale about a group of sisters dealing with the challenges of puberty in a small, conservative seaside village. This time around, up the road from the buzz of the Julian Barratt’s delirious Mindhorn, opening night gave us another intimately observed film about a coterie of young girls on the cusp of adulthood. The subjects of All This Panic, directed and shot by Jenny Gage and her cinematographer partner Thomas Betterton, are not subject to the same level of lock-and-key control and captivity, the six girls…