Give a defined exit status (defaulting to "0").

refs #209
Suppress message in case the QM has already quit.

resf #209
Write proper marks to the logfiles.

Which can be used to find back the entries of a given session.

refs #209
Fix quoting.

refs #209
Move exit message into cleanup function.

refs #209
Workaround for bash bug not updating the joblist.

refs #209
Change to "run/" dir before starting the QM.

refs #209
Exit non-zero in case *we* did not stop the QM.

Which implies that it was explicitly killed or has crashed.

refs #209
Show errorlog excerpt in case of QM quitting unexpectedly.

refs #209
Replace non-working status check with explanation.

With the recent commits it is in fact not necessary to check the status of the
QM right after starting it up as it will anyway get checked directly in the
endless loop. Plus, it did not work anyway ;)

refs #209