Add syslog support, fix verbose for mongo

* Fix verbose hardcode to be controlled by verbose global
* Add support for syslog (controlled by use_syslog global)
  Syslog facility is default (user), hence the local logs
  will go to the /var/log/user.log.
  Remote logs will go to /var/log/remote/node*/mongo*.log

Closes-bug: #1317080

Change-Id: I79a32b18a1c601c40f695fb0266fab6ca2cc8906
Signed-off-by: Bogdan Dobrelya <bdobrelia@mirantis.com>
Merge "Add syslog support, fix verbose for mongo"