Convert blankanontalks.py to the distributor concept.

To test:

* Copy ~dbreps/.dbreps.ini to test.ini.
* In test.ini:
** Change "[dbreps]" to "[enwiki]".
** Change "rootpage: ..." to a sandbox.
* Change directory to your Git checkout.
* "./dbreps -c /path/to/test.ini -r general.blankanontalks -s enwiki"

Do not merge this pull request yet!