SLING-2742 Adds RepositoryStatisticsMBean which wrapps the RespositoryStatistics from Jackrabbit in an MBean.

git-svn-id: https://svn.apache.org/repos/asf/sling/trunk@1450019 13f79535-47bb-0310-9956-ffa450edef68
SLING-2742 added NPE protection should the repository method not be accessable.

git-svn-id: https://svn.apache.org/repos/asf/sling/trunk@1450020 13f79535-47bb-0310-9956-ffa450edef68
SLING-2742 refactored so that there is 1 stats bean per repository.

git-svn-id: https://svn.apache.org/repos/asf/sling/trunk@1450021 13f79535-47bb-0310-9956-ffa450edef68
SLING-2742 adjusted the JMX object names to make all sling objects appear in the same tree.

git-svn-id: https://svn.apache.org/repos/asf/sling/trunk@1450022 13f79535-47bb-0310-9956-ffa450edef68
SLING-2751 Fixed JMX names for event JMX objects.

git-svn-id: https://svn.apache.org/repos/asf/sling/trunk@1450023 13f79535-47bb-0310-9956-ffa450edef68