AdminP - change handling of job document

[rsoika]

The AdminP service currently put the adminp document to the corresponding job handler. But it did not save the adminp document after completion. We have implemented a lot of save methods in the job handlers. This makes no sense and makes it more complex to implement a custom job handler.

The AdminP service should save the adminp document by himself after the jobhandler terminates.
We need to define the reserved job fields:

• type - fixed 'admin'
• job - job type field defined by handler
• isCompleted - boolean indicates if job is completed - controlled by job handler

The AdminP process should update the status before giving the adminp document to the handler and update the status again after finishing.
The return value should be the adminp document.

[rsoika]

docu update needed