replace log4j dependencies w/ log4j2
log4j2 configuration
Merge remote-tracking branch 'origin/master'
transition to log4j 2
Revert "Merged logging-log4j from upstream/fix-logging."

This reverts commit ceec1c5585912251578bc78bc93287f2d4e766c7.
Merge remote-tracking branch 'origin/master' into features/clustering
 commit ceec1c5585912251578bc78bc93287f2d4e766c7.
Use slf4j bindings instead of log4j in Hazelcast.