harpoon-agent: /resources includes reserved

Resolves #6
Merge pull request #20 from soundcloud/remove-docker-system-import

container: update for changes to docker repo
Merge pull request #12 from soundcloud/agent-resources-includes-reserved

harpoon-agent: /resources includes reserved
agent: remove restart command

Other, somewhat random changes:

- Clarify agent/container heartbeat state machine transitions
- Naming convention stuff (request channels in container)
- Code style stuff (all over the place)
scheduler: add basic registry persistence

- Write the current "scheduled" map to a file whenever it mutates
- Load that file when creating a registry
scheduler: scheduling algo takes, not closes over, state
agent: cherrypick host resource accounting from master
agent: heartbeat from unknown container yields FORCEDOWN
agent: re-order validation switch statements
container: use new, fewer states in Heartbeat and state machine
container: coordinate shutdown with agent
Merge pull request #23 from soundcloud/agent-restart-redux

agent: remove restart command
Merge pull request #24 from soundcloud/scheduler-persistence

scheduler: add basic registry persistence
Simplified as per Bernards review comments.
Merge branch 'master' of github.com:soundcloud/harpoon into logging-api

Conflicts:
	harpoon-agent/container.go
Fix latent bug in registry save code.
Corrected imports ordering.
Merge pull request #26 from soundcloud/jmy-fix-registry-save

Fix latent bug in registry save code.
agent: use /api/v0 prefix on all routes, per spec
scheduler: improve remote agent state machine semantics