Implement image fingerprint database for detecting reposts

[FoxxMD]

May be worthwhile to replicate repost sleuth bot on a (much) smaller level IE subreddit/bot level.

Things that would need to be or need to be considered...

• [ ] Support more than just redis for database?
• [ ] Definable (but optional) collections EX known spam, retired memes, all subreddit posts, etc...
• [ ] UI requirements
  • [ ] Upload image by file or URL
  • [ ] Batch upload from local directory?
  • [ ] Progress indicator for processing
  • [ ] Stats (number of fingerprints, search peformance)
• [ ] Rule refactoring to allow searching all, by collection, and/or user history
• [ ] user-configurable if database should be shared across bot/instance