Wrap all sources in a namespace

[fosterbrereton]

To eat our own dogfood here, the sources should be wrapped in a namespace to minimize the chances of ODRVs happen. For source-level structures and algorithms, they should be wrapped in an anonymous namespace (I believe most - but maybe not all - already are.)

[kc9jud]

Somehow it feels appropriate that this project should have a CI config that builds the source, and then runs the built artifact on its own source.

Maybe if I get some time I'll come up with a PR.

[fosterbrereton]

Eating our own dogfood here sounds amazing.