Function healpixRingToNest( k, ringIndex )

Description:
Converts a healpix ring index from the RING to the NEST scheme at a given order.
Parameters:
k (integer)
HEALPix order (0..29)
ringIndex (long integer)
pixel index in RING scheme
Return Value (long integer):
pixel index in NEST scheme
Signature:
long healpixRingToNest(int, long)