More agreement testing
Treat pronouns as determiners rather than nouns
Allow elided verbs in auxiliary contexts

E.g., "Can the boy?" or "I should have been."  The verb lambda is a
metaoperator "AGENT", which describes the relationship between the
subject and the unspecified event.
Make it easier to copy DCG output into test results
Unit tests and fixes for modality/aspect

Fixed:
- checking finiteness for do-support
- logical operator for `be'
Aggregate errors and print them all after testing