Fix several logging related issues

Addresses logging problems in which log output from libraries
were not logged through the logging system used by dCache.

- Suppress import of log4j and commons-logging
- Use new version of logback for testing too
- Use SLF4J extension for liquibase
- Adjust default log level for liquibase

Target: trunk
Require-notes: yes
Require-book: no
Acked-by: Tigran Mkrtchyan <tigran.mkrtchyan@desy.de>
Patch: http://rb.dcache.org/r/5085/
Committed: master@39cec783d0a9fcfc7984109de8c58991aeb6ebff