Remove global variables from harpoon-agent.
harpoonctl: improve config help
Variable names, for consistency/brevity
Variable names, for consistency/brevity
Merge pull request #128 from soundcloud/agent-deglobalization

Remove global variables from harpoon-agent.
Copy r.subscribers map and release lock before sending updates to
subscribers.
Explanatory test comment.
Merge pull request #136 from soundcloud/fix-agent-registry-deadlock

Fix registry deadlock
Merge branch 'master' of github.com:soundcloud/harpoon into async-artifact-download

Conflicts:
	harpoon-agent/main.go