I didn’t expect that a documentary about two Canadian naturalists and adventurers in their 90s would be a such a feel-good film. But that’s what director Alison Reid (The Woman Who Loves Giraffes)has delivered with this uplifting, eye-opening and altogether charming portrait of Robert Bateman and Bristol Foster, childhood friends who in 1957 set off in a custom Land Rover that they whimsically named the “Grizzly Torque” after a “Pogo” comic.