added getLatestChangeLogToken() and more JavaDoc

git-svn-id: https://svn.apache.org/repos/asf/chemistry/opencmis/trunk@1525926 13f79535-47bb-0310-9956-ffa450edef68
Workbench: added QR code for content link

git-svn-id: https://svn.apache.org/repos/asf/chemistry/opencmis/trunk@1525927 13f79535-47bb-0310-9956-ffa450edef68