refactor(agent): Move logic from HandleEventJobOffered to MaybeBid
refactor(agent): Move logic from HandleEventJobScheduled to JobScheduled
refactor(agent): Move StopJob locking into Agent
refactor(agent): Move logic from HandleEventJobUnscheduled to JobUnscheduled
refactor(agent): unexport Agent.UnloadJob
refactor(agent): Drop Agent.Machine()
refactor(agent): unexport Agent.LoadJob
refactor(agent): unexport Agent.Bid
refactor(agent): Split JobScheduled into JobScheduledElsewhere/Locally
refactor(agent): unexport Agent.BidForPossibleJobs
refactor(agent): unexport Agent.FetchJob
fix(agent): Drop unnecessary call to VerifyJob
refactor(agent): unexport Agent.VerifyJob
refactor(agent): unexport Agent.BidForPossiblePeers
refactor(agent): unexport Agent.AbleToRun
refactor(agent): Acquire AgentState lock during Initialize
refactor(agent): Acquire AgentState lock during Purge
Merge pull request #469 from bcwaldon/agent-logic

Refactor Agent/EventHandler relationship
feat(fleetctl): add custom fields option to list_units