Currently logging configuration is splitted in two distinct classes, the init.pp
and the logging.pp classes.
This review aims to centralize all logging related parameters in a single class,
the logging.pp one.
The impacted parameters are :
* use_syslog
* use_stderr
* log_facility
* verbose
* debug
* log_dir
* log_file
This change remains backward compatible with what is currently in place
Change-Id: Ic268104fd9bc77bc142fc635285b0459f3d4314f