Perhaps it could be avoided to include an author with multiple posts (per post or per day).

I added some new checks along this line. Now, the operator can set a limit on how many times an author appears per post, per day, and per week. Also, there's a new limit on how many times a post appears per 30-days. We'll see how these new limits work out going forward.

First pass, I'm using python sqlite for the history, but I am thinking of moving that info to a linked list in custom_json transactions so that Thoth can move between computers without losing its history. (Setting up a linked list to avoid scanning the blockchain was @cmp2020's idea)