Add local blacklist function

[spiral6]

If the author has commented in their submission and that comment includes the string "mirror" in it, then the bot shouldn't comment.

Rather, if the user sends a message to the bot containing the string "add to blacklist", the bot will save the user's name in a blacklist file, like blacklist.cfg. If the submission is by a blacklisted author, do not comment, and skip that submission.

[spiral6]

Updated issue.

[kupiakos]

I use Heroku to host the site, and I currently don't have persistent storage set up, so Lapis doesn't currently store any permanent information. I'll have to take a look into it.

[spiral6]

I think I have a working implementation of this, I'm going to test it on a test sub of mine, and if it does work, I'll do a pull request.

[kupiakos]

As stated, it needs to work in Heroku to be accepted.

[spiral6]

Sure. It might be through SQL that it could be done. In which case my local text file case wouldn't work that well. SQL probably would. I'm going to test it with SQLite, and if it works there, it might just need a bit of tweaking to work on Heroku.