corrected liveness of Refresher class
first implementation and a little bit tested of the synchronous reply on getLastData method in the Device Channel

Signed-off-by: Claudio Bisegni <Claudio.Bisegni@lnf.infn.it>
fix the synchronous answer on directio

Signed-off-by: Claudio Bisegni <Claudio.Bisegni@lnf.infn.it>