added MemberAttributeConfig serialization via XML

1. hazelcast-spring serializaion (see hazelcast-spring-3.3.xsd)
2. hazelcast serialization (see hazelcast-config-3.3.xsd)
fixing checkstyle issues
fixing checkstyle issues: tabs removed
Merge branch 'master' of https://github.com/dsukhoroslov/hazelcast.git

Conflicts:
	hazelcast/src/main/java/com/hazelcast/config/MemberAttributeConfig.java
more tabs removed
Prevent NIO threads to execute and/or invoke any operation.
Add test for issue #2980
Improved EventService, made executeEventCallback() method part of SPI.
Call connection listeners as event callback instead of calling them directly on IO thread.
Test fix.
CheckReplicaVersion should not be an urgent operation, to make in order with backup operations.
ClientLockWithTerminationTest should warmup all partitions before testing node crash.
Merge pull request #3006 from mdogan/fix/3.3/redundant-replica

CheckReplicaVersion should not be an urgent operation, to make in order ...
checkstyle fix
Merge pull request #2792 from dsukhoroslov:master
Very first draft of SPI section
Grammar revisions.
Text revisions.
Merge branch 'master' of https://github.com/hazelcast/hazelcast
Merge pull request #2994 from mdogan/fix/3.3/tcp-nio

Fixes operation execution/invocation on IO threads issue