Merge pull request #4 from akhayrutdinov/BACKLOG-1495

[BACKLOG-1562] Add support for ACL shadow nodes in repository
[BACKLOG-1574] - Add the ability to provide configuration to store the data source acl nodes.    Property aclNodeFolder added. Can be retrived via PentahoSystem.get( ISystemConfig.class ).getProperty(repository.aclNodeFolder);
Merge pull request #5 from Pedro-Entrezede/BACKLOG-1574

[BACKLOG-1574] - Add the ability to provide configuration to store the data source acl nodes.
[BACKLOG-1562] Add support for ACL shadow nodes in repository - added removeAclNode()