Bhutan develops with an eye to spiritual heritage 

By CHAITANYA KALBAG   of Reuters   through NZPA   Thimphu, Bhutan   on many mountainsides in the tiny Himalayan kingdom of Bhutan, Buddhist prayer wheels powered by streams tumbling through birch and pine trees spin in endless movement.   The wheels turn on present-day gear shafts that speak of modern Bhutan, moving slowly towards development and yet rooted in…