Querying abstractions that 'need review' or are 'reviewed' should not consider 'blanked' abstractions 'reviewed'.

[mgurley]

An abstraction with a value equal to an empty string should not be considered 'reviewed'. Ideally, each abstraction would either have an actual value or be null, but right now it is very possible for an abstraction to end up with an empty string as a value. The system should pester the user to not leave an abstraction in such an ill-defined state.