HBASE-9033 Add tracing to ReplicationSource and enable it in tests

git-svn-id: https://svn.apache.org/repos/asf/hbase/trunk@1506638 13f79535-47bb-0310-9956-ffa450edef68
HBASE-9036 Few small code cleanup (Jean-Marc)



git-svn-id: https://svn.apache.org/repos/asf/hbase/trunk@1506669 13f79535-47bb-0310-9956-ffa450edef68