refactor(getRegistry): Remove unused parameter in `getRegistry`.
fix(fleetctl start): Allow to start jobs that have been scheduled already.
Merge pull request #177 from calavera/remove_registry_context_dependency

refactor(getRegistry): Remove unused parameter in `getRegistry`.
Merge pull request #163 from calavera/update_job_on_failed

Allow to restart units with failed state. Fix #127.
feat(ssh): ssh detects unit or machine automatically
Merge pull request #175 from calavera/ssh_detect_machine_or_unit

feat(ssh): ssh detects unit or machine automatically
refactor(unit): Use all options provided in unit file

This requires a new format in a Registry, but it maintains
support for the old format for now.
refactor(payload): separate Payload registry code
refactor(payload): push legacy payload logic into registry
wip version negotiation