[KDevPlatform] bae38ce: Use pthread directly for the foreground mutex, pot

[Syron]

After reading that bug report, I do not think that QMutex has a bug.
I've seen that there are only consistency checks done if Qt is
compiled without QT_NO_DEBUG, and theses checks should cover the case
where - due to a switched lock/unlock or too many calls to unlock -
QMutex::d->count wraps around 0 to ~0 on decreasement. So a call of
unlock before lock could cause these deadlocks.
-- Syron