[base] Socket: added `bool Socket::isOpen() const` as a convenience-method
[base] Socket: added `bool Socket::isOpen() const` as a convenience-method

xzero/x0,xzero/x0,xzero/x0,christianparpart/x0,christianparpart/x0,xzero/x0,christianparpart/x0,christianparpart/x0,christianparpart/x0,christianparpart/x0,xzero/x0,christianparpart/x0,xzero/x0