Improvements to the main executable:
- Better separation of code, no modificable globals.
- Smarter threading.
- Progress feedback on long tasks, optional.
- Added options: --list-tags, --repository, --exclude-repository, --no-progress, -v.
- Removed options: --no-ccr, -u.
- Removed Wikidata support for a KISSer implementation.

Also:
- Added Sphinx support and complete documention.
- Included a requirements.txt file.