Ensure defunct connections are completely closed (JAVA-394).
Fix memory and resource leak on closed Sessions (JAVA-342, JAVA-390).
test for session and connection leaks
Decommission node added for connectionsLeak test case
Move sessionMemoryLeakTest to the "long" group.
Merge branch 'joaquincasares-JAVA-342-test' into 2.0
Add comments for recent JAVA-342 tests
Merge remote-tracking branch 'upstream/2.0' into 2.0