Added failure reason to DB

* notifyUpdate will check the daemon is running prior to send a success
* if any failure reason is passed, then a failure is recorded
* Unit tested :)
Added saveReload method to EBox::Module::Service

+ Mimetise EBox::Module::Base::save but reloading instead of restarting
+ Added saveReload method to use reload instead of restart to
  reduce service downtime. Use with care and programatically