refs #380, QConcurrent vs QThread sample and fix

* in same step fixed nullptr issue in worker (with no parent)
* Changed from QConccurennt::run to CWorker in core

src/blackmisc/worker.h

@@ -249,7 +249,7 @@ namespace BlackMisc
         void ps_finish();
 
     private:
-        QObject *m_owner;
+        QObject *m_owner = nullptr;
         QString m_name;
     };