[platform-ui-dev] API change to Job.setSystem and Job.setUser

[John Arthorne <John_Arthorne@xxxxxxxxxx>]

If you are using the platform concurrency
infrastructure (org.eclipse.core.runtime.jobs.Job), read on.  Others,
please disregard.

I have made an API change to the methods
Job.setSystem() and Job.setUser(). These methods must now only be called
BEFORE the job is scheduled. If you change these values after the job is
scheduled or while it is running, they will fail. This was causing refresh
problems in the UI (jobs showing in the progress view when no longer running,
or running jobs not appearing in the progress view). We have been entering
individual bug reports for the places where we have found this occurring,
but implementors of system jobs should also double-check that they are
not doing this.  This change will be released for the next integration
build. See also:

https://bugs.eclipse.org/bugs/show_bug.cgi?id=58533