Checkstyle fixes
fixed npe on ownerConnection in clientConnectionManager
This fixes #2759, messages about management center connectivityjustified
Merge
client tests edited & generic null check method added
Fixes #2759, checkstyle issues
Moved transaction request package to com.hazelcast.transaction
removed ProblematicTest marker from the tests not failed recently
Fixed checkstyle issue with ClientTxnportableHook
Minor checkstyle improvement
log refactor
fixes #3178
added test for remove
added unit tests
Fixed automatic renaming issue; requests -> client -> requests
fix checkstyle
Merge pull request #3223 from emrahkocaman/master

Management center connection messages justified
Null checks for MultiMap methods
client tests edited & generic null check method added
Merge branch 'null-check-multimap' of https://github.com/buremba/hazelcast into null-check-multimap