Added
- definition for qualifiers (negation, plausibility, temporality, experiencer)
Changed
- updated rules for context algorithm to be consistent with definitions
- added some rules for context algorithm
- refactored `Qualifier` class from enum to a separate class, that accomodates other fields (like prob)
- use `entity._.qualifiers` to obtain `Qualifier` classes, `entity._.qualifier_str` for strings, and `entity._.qualifier_dict` for dicts
Fixed
- ambiguity of `dd` for context rules (can mean differential diagnosis, and daily dosage)
- importing `clinlp` caused a bug when extras were missing