hist-server: user interruption handling
In this merge request a proper finishing of the histogram server on the application termination induced by a user.
If the histogram server execution interrupted, the zmq::error_t with error number EINTR is thrown. This error is cought in the Appliacation::Exec() and stops listening to the messages.
Edit PAL: Redmine refs #3253
Edited by Pierre-Alain Loizeau