D2 dlsproto

[gavin-norman-sociomantic]

This issue is automatically created to act as a card for
Sociomantic D2 migration project board.

All other issues and pull request in this repository that are related to D2
migration should be referenced from this issue. It is highly appreciated
to provide short status reports on any breakthroughs in form of issue comments.

Please adjust this issue column in https://github.com/orgs/sociomantic/projects/4
board to reflect current stage.

If this is not a D project (GitHub language detection is imperfect), please
both close the issue and remove matching card from the linked project.

[gavin-norman-sociomantic]

Stage 4 (used by an app that is at stage 4). Closing.