Set rabbit's log_level = syslog_log_level global

Rabbit doesn't support syslog directly, thus its log level for rsyslog::imfile logfile monitor
should always be >= syslog_log_level, otherwise none rabbit's messages would have gone to syslog.

Signed-off-by: Bogdan Dobrelya <bogdando@mail.ru>
Add imfiles for rabbitmq startup/shutdown errors

Signed-off-by: Bogdan Dobrelya <bogdando@mail.ru>
Merge branch 'fix_todos'