- adding freemarker expression for output path patterns
- enabling using the same rendering engine template with multiple mime types
- extracting rendering engine template from rendering engine to make moving to templateservice easier eventually
git-svn-id: https://svn.alfresco.com/repos/alfresco-enterprise/alfresco/BRANCHES/WCM-DEV2/root@4351 c4b6b30b-aa2e-2d43-bbcb-ca4b014f7261