Update UI control elements from vehicle, allows multi-operator mode

src/uas/UAS.cc

@@ -161,6 +161,7 @@ void UAS::receiveMessage(LinkInterface* link, mavlink_message_t message)
                     this->status = (int)state.status;
                     getStatusForCode((int)state.status, uasState, stateDescription);
                     emit statusChanged(this, uasState, stateDescription);
+                    emit statusChanged(this->status);
                     stateAudio = " changed status to " + uasState;
                 }
 

src/ui/uas/UASControlWidget.cc

@@ -181,7 +181,7 @@ void UASControlWidget::cycleContextButton()
     if (mav)
     {
 
-        if (engineOn)
+        if (!engineOn)
         {
             ui.controlButton->setText(tr("Stop Engine"));
             mav->setMode(MAV_MODE_MANUAL);