Added support for processed job status in event
Updated according to comments
removed intent
Moved the constants back to worker
Move job status codes to worker event
Add "unknown" status and use for unitialized jobs

Add a 0 status for jobs which have an unknown status and use this
status instead of a NULL value.
s/JOB/JOB_STATUS/g
Add test to assert return value from job
Add documentation about job status codes
Update CHANGELOG with job status codes
Merge pull request #104 from juriansluiman/feature/job-status

Added support for processed job status in event nr2