Changes as follows:
 - fixed some bugs in qccpd.py under Ian's supervision
 - can't remember the changes to qcgf.py
 - added qcio.xlsx_write_series;
   - uses xlsxwriter when the number of records
     to be written to the Excel file exceeds 65535
   - works but is slow
 - added aws2nc.py;
   - script to format BoM AWS data into OzFlux netCDF files