If the early years of the second decade of the 21st Century are looked back on by culture historians and future mars-dwelling anthropologists, then the most striking thing that hopefully hits them isn’t just our society’s over-reliance on dance bangers and international rappers but also the grey period that alternative music went through. Alt-J, Metronomy and to a lesser extent Future Islands are helping build up a series of strong copyright cases by releasing each other’s songs; weak bladdered knock-offs of LCD Soundsystem which although not terrible, aren’t anything special. Into the fray step Jungle. Jungle starts off promisingly enough.…