Minor code review as part of [[WP:BRFA/Legobot 13]].
Minor code review as part of [[WP:BRFA/Legobot 13]].

- Fix bug when pages are moved within the AFC space, which should
  not be tagged.
- Use built-in datetime manipulation functions. Solves a potential
  problem when now.hour == 0, and is cleaner.
- Use UTC for timestamps instead of local time.
- Removed unused os import.
- Some misc cleanup with spacing, etc.

legoktm/pywikipedia-scripts