refactor(state): Rename JobState to PayloadState
refactor(job): Rename Job.State to Job.PayloadState
refactor(registry): Use alternate model for Job marshalling
refactor(state): Rely on Job for PayloadState

PayloadState belongs to a Job, so without a Job a PayloadState object
is useless. Rather than allow clients of the Registry to ask for
PayloadState specifically, force them to get it through GetJob.
Merge pull request #321 from bcwaldon/payload-state

Refactor JobState into PayloadState, owned by a Job
refactor(payload): Interact with Jobs, not Payloads

Payloads are not separate entities, they belong to Jobs. Calling code
should not have to explicitly create payloads in the registry.

This breaks the `fleetctl submit` behavior, as creation of the Job
earlier in the workflow is triggering it to get scheduled and
automatically started. This will only be broken temporarily.
Merge pull request #322 from bcwaldon/job-encapsulates-payload

refactor(payload): Interact with Jobs, not Payloads
refactor(fleetctl): move to new simpler CLI framework

- Remove all codegangsta/cli usage from fleetctl
- Create simple Command struct
- All commands return exit code and os.Exit is only called by main() (#275)
- Dramatically simplify flag usage by accessing flag variables directly
- Implement top level "help" + "version" commands
- Simplify glog usage by using its built-in global options
- Fix small output formatting issues in some commands
- Delay SSH tunnel establishment (#309)
- Fix SSH panic (#317)
refactor(fleetctl): make usage more generic; use pointers instead of copies
refactor(fleetctl): remove globalconf and simplify env global options
refactor(fleetctl): use anonymous structs for storing global/shared flags
refactor(fleetctl): remove pflag reference since for now we don't care about short flag names
refactor(fleetctl): several more changes to CLI cleanup

- add custom global flagset so that glog's flags are hidden
- add global "--verbosity" flag, passed directly to glog
- add global "--debug" flag back, make equivalent to --verbosity=2
- document Command struct
- fix Usage and Description for every command
- use exit variable in runStatusUnits
- run gofmt against everything