support logging to local file and stdout

Currently columnstore only supports logging to syslog. It should be additionally possible to support:

• Logging to a local file without syslog and provide some simple script / documentation for log rotation.
• Logging to stdout. This would be make it much easier to integrate logging in a docker container.

MariaDB server does not utilize syslog by default though can be configured to do so, so this is also a necessary step towards convergence.