This method follows the Atom Publishing model where the entry document, atom or cmis, is posted to the root or specific folder URI.  For unfiled documents, post the document to the unfiled collection.   The document will be created in the folder posted. If the document is posted to the root collection and a folder property is specified, then the repository will create the document in the specified folder.  If the content stream is specified on create, it should be base64 encoded in the atom entry.