* agent: return a non-zero exit code on error
* agent/template: always return on template server error, add case for error_on_missing_key
* agent: fix tests by updating Run params to use an errCh
* agent/template: add permission denied test case, clean up test var
* agent: use unbuffered errCh, emit fatal errors directly to the UI output
* agent: use oklog's run.Group to schedule subsystem runners (#9761)
* agent: use oklog's run.Group to schedule subsystem runners
* agent: clean up unused DoneCh, clean up agent's main Run func
* agent/template: use ts.stopped.CAS to atomically swap value
* fix tests
* fix tests
* agent/template: add timeout on TestRunServer
* agent: output error via logs and return a generic error on non-zero exit
* fix TestAgent_ExitAfterAuth
* agent/template: do not restart ct runner on new incoming token if exit_after_auth is set to true
* agent: drain ah.OutputCh after sink exits to avoid blocking on the channel
* use context.WithTimeout, expand comments around ordering of defer cancel()
The result will still pass gofmtcheck and won't trigger additional
changes if someone isn't using goimports, but it will avoid the
piecemeal imports changes we've been seeing.
