Release v1.15: attrname calculator export.

Start of development for release 1.16.

Release v1.14: nomina mutables export, diagnostic hardening.

Release v1.13: attribute explanations, internal names, 3.15 support.

Start of development for release 1.15.

Start of development for release 1.14.

Release v1.12: ABC support and protocol hierarchy repairs.

Start of development for release 1.13.

Release v1.11: Export type aliases for downstream consumption.

Start of development for release 1.12.