SONChanDelete

  SONCHANDELETE deletes a channel from a SON file
      RET=SONCHANDELETE(FH, CHAN {,QUERY})
          FH = file handle
          CHAN = channel number 0 to SONMAXCHANS-1
          QUERY (if present) =  0 Do not query
                             <> 0 Query before deleting (default)
  Returns 0 if deletion successful, negative error code otherwise

  Author:Malcolm Lidierth
  Matlab SON library:
  Copyright © The Author & King's College London 2005-2006