Updates to Event, EventChain, and NarrativeSchema to make scores and be able to add any verb encountered to a schema. Pair and Triple updated to have equality and hashes. Beta and lambda introduced to CountEvents
Also clarified the use of Protagonist pro in EventChain. This is only to mark the fact that this protagonist was assigned to the chain for a document. NarrativeSchema allows you to force-add events (creating new chains or adding to old ones) using this fact.