Ensure that each slave is correctly exposing front facing and back facing logs with tests. Optionally request frontend from each node to expose logs nicely, instead of hardcoded approach.

Tasks:

• expose and test for frontend-facing log
• expose and test for backend-facing log
• adapt logging done by rsyslogd, as maybe there is needless duplication of timing
• request real slave frontend for nice access will be done in !791 (merged)
• review the way how information is returned to the slave requester
  • it's ok for now
• review log retention
• update documentation no changes needed
• update changes no changes needed