131716 cturlica: REPO-1404: Improve extensibility of NodesImpl
- refactored the listChildren by adding dedicated filter and sort methods, also added protected getters for the services and repositoryHelper.
git-svn-id: https://svn.alfresco.com/repos/alfresco-enterprise/alfresco/HEAD/root@132288 c4b6b30b-aa2e-2d43-bbcb-ca4b014f7261