Issue #301 - Validate consistency of count_by
Merge pull request #426 from ambiata/topic/reduction-properties

Validate consistency of count_by
Merge identifier variants whilst keeping compatibility.

This will smoothly migrate all identifiers to V2.

Fixes #56.
Fixes #79.
Fixes #149.
Merge pull request #420 from ambiata/topic/one-identifier

Merge identifier variants whilst keeping compatibility.
Better data-types.
random