contrib/schema: update generator to rewrite imports
contrib: vendor google-api-go-generator with godep \o/
schema: fix spelling idiocy
schema: remove old generated API json
job: add IsGlobal to job.Unit/fleetctl, and associated test coverage
Merge pull request #782 from jonboulle/schemaglobal

schema: add IsGlobal and associated tests
Merge pull request #777 from jonboulle/googleapi

contrib/schema: update generator to rewrite imports
agent: add UnitStatePublisher.Purge
Merge pull request #787 from bcwaldon/purge-USP

agent: add UnitStatePublisher.Purge
agent: simplify desired state construction
agent: move task-related code to task.go
agent: serialize tasks through taskManager
agent: model dependent tasks using taskChains