Null checks for MultiMap methods
client tests edited & generic null check method added
fixes #3178
added test for remove
fix checkstyle
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
moved tests to MapStoreTest
Added a separate delete method for RecordStore
renamed ValidationUtil.checkIfNull method
better renaming & cleanup
Merge branch 'master' of https://github.com/hazelcast/hazelcast
Start tx in a new thread since {@link com.hazelcast.transaction.impl.TransactionImpl#THREAD_FLAG} is thread local and during node shutdown thread flag does not cleared. This is the reason of failures in repetitive test calls from same thread.
WIP
Merge branch 'master' of https://github.com/hazelcast/hazelcast
use unmodified field during sorting
fix #3257 : WIP
Merge branch 'master' of https://github.com/hazelcast/hazelcast
Fixes #3257 : config validation

Fixed the issue that not a lot of config validation is done. It also fixes the issue
that in some cases instart of shutting down the node, due to the config conflict, a
seperate cluster is created.

This patch doesn't contains logic for structural checking of conflicts for map/queue
etc. But it does contain all the infrastructure.

It also contains the feature where a user can provide a 'token' to that needs to be
the same on all members. E.g. filepath or other configuration settings. This can be
done through the hazelcast.application.validation.token system property.