- Fix test compilation in release mode (@avsm #262, reviewed by @mtelvers)

- Update Dockerfile.worker and Dockerfile.worker.alpine base images (@mtelvers #261 #260)

- Constrain capnp-rpc-* < 2.0 (@mtelvers #259)

- Add HCS backend support for Windows containers (@mtelvers #258)

- Add x-maintenance-intent to opam metadata (@mtelvers #257)

- Add QEMU backend (@mtelvers #253, reviewed by @shonfeder)

- Improve Lwt exception handling (@MisterDA #250, reviewed by @shonfeder)

- Update bundled obuilder; mark it as vendored (@shonfeder #247, reviewed by @mtelvers)

- Retry on failed docker push, with new Lwt_retry utility (@shonfeder #246, reviewed by @mtelvers)

- Update base image and opam SHA (@mtelvers #245)

- Async delete in worker prune path (@mtelvers #243)