Simpler handling of click-buttons (as opposed to toggle buttons)

[cdyk]

Buttons are backed by a bool value that are set to true when the button is clicked. However, the application must set it back to false to make it a click-button, i.e. in the listener:

bool value;
stateElement->getValue<bool>( value );
if( value ) {
    // do stuff...
    m_model->updateElement( stateElement->getKey(), false );
}

and this has to be repeated for all click-buttons.

Avoiding this clutter in the job-code would be nice.