Add default conflict resolution

[Vernalhav]

Should this be solved at the parsing table level (as in there always being exactly one Action for each transition) or at the parser level (as in having a actions.Conflict action that stores all possibilities), to be disambiguated by the parser?

[Vernalhav]

The actions.Conflict approacah is interesting because it allows for other components to interact with it (such as logging the conflicts to the user outside of the table creation routine). Otherwise, an events-based approach would work to decouple the conflict logging logic, but it doesn'r seem too Pythonic.