Adding a minimal implementation of cmis:item so getAllTypes does not throw exceptions.

git-svn-id: https://svn.codespot.com/a/apache-extras.org/alfresco-opencmis-extension/trunk@37 896628b3-2344-bb7d-e986-543e3a70545d
Merge branch 'trunk'
Depending on current OpenDataSpace CMIS