Add in duplicate link detector
Add in duplicate link detector

Uses beautifulsoup4. Doesn't slow things down (maybe 0.002 of a second)
so I think it's okay.

NickVolynkin/SmokeDetector,NickVolynkin/SmokeDetector,Charcoal-SE/SmokeDetector,ArtOfCode-/SmokeDetector,ArtOfCode-/SmokeDetector,Charcoal-SE/SmokeDetector