kjob: stop implicitly applying a QEventLoopLocker
as it turns out the implicit locker is really just wrong half the time.
In drkonqi it caused premature quits. In plasma-discover it prevents quits on stuck downloads of json blobs.
and it's alltogether questionable behavior for a coreaddons level class. KJob cannot possible know if the caller (or indeed more specifically: the app) requires that a job be finished or aborted.
you may ask "couldn't the app just abort the job when they need aborting behavior?" and indeed it could, the trouble is that between the app and the job may be additional layers that need to facilitate this.
quick example: plasma-discover uses knewstuff, knewstuff uses kio, kio uses kjob. for discover to have control over the job, the job either needs surfacing in the API of 2 frameworks or the frameworks need to provide bespoke means to terminate the job without surfacing the fact that there is a job.