SSDM-2464: Logging too verbose on AS & DSS

datastore_server/dist/datastore_server.sh

openbis/dist/server/base/lib/logging/log4j-1.2.17.jar

openbis/dist/server/base/lib/logging/slf4j-api-1.6.6.jar

openbis/dist/server/base/lib/logging/slf4j-log4j12-1.6.6.jar

openbis/dist/server/base/modules/logging.mod

openbis/dist/server/base/resources/.gitignore

openbis/dist/server/base/resources/jetty-logging.properties

openbis/dist/server/base/resources/log4j.properties

openbis/dist/server/base/start.d/logging.ini

openbis/dist/server/startup.sh