“If you need to know everything upfront, you’ll never get off this land,” Javier (Cliff Curtis) can be heard telling Julija (Gracija Filipovic) in “Murina,” just after arriving at the island home off the coast of Croatia where the 19-year-old lives with her domineering father Ante (Leon Lucev) and her deferential mother Nela (Danica Curcic).