detSubStruct
Focus:
BoaFocus.py
NAM: detSubStruct (method)
DES: determine the structure of the scan = first and last index
of each observation (=subscan)
INP: (int) chan = channel
(int) flag = flag to be used (0=unflagged)
HIS: MA040405 initial version
SM040514 with Marcus Albrecht: first runnig version