Retroactive Advantage — Black Flag / Tales of the Valiant (ToV)

Adds Advantage / Normal / Disadvantage re-roll buttons to d20 chat messages in Black Flag Roleplaying (Tales of the Valiant) for Foundry VTT. Players can retroactively change their roll's advantage mode without re-rolling from the sheet. Ported from the D&D 5E Retroactive Advantage module.