This is a port of HSC-1106
When running tasks that write out config settings files (processCcd.py, for example), if multiple processes start simultaneously, an I/O race condition can occur in writing these files. This is solved here by writing to temp files and then renaming them to the correct destination filename in a single operation. Also, to avoid similar race conditions in the backup file creation (e.g. config.py~1, config.py~2, ...), a --no-backup-config option (to be used with --clobber-config) is added here to prevent the backup copies being made. The outcome for this option is that the config that are still recorded are for the most recent run.