Repaired version of './digcheck.py':
- verified with 'jonah.net' and 'ns.unc.edu'
- verified with 'archie.net' and 'anthony.net'
- added file outout of difference data to '$zonename_diff_file.data'
  - using 'DataTools.txt2file()' for file output

New feature added to DataTools.txt2file():
- 'append' is done with flag '1' as final parameter:
  - DataTools.txt2file(txt,fillename,1)