Retrieves the URL for uploading an attachment. This URL is time sensitive. It must be invoked as a PUT with the attachment converted to a byteStream within the request body. The attachment ID is returned in location attribute of the PUT call's response header.

Note: If you have document conversion turned on, the attachment ID is returned in the native format initially, then goes through a conversion. Once converted, the native attachment ID will no longer be valid and it will be replaced with a GUID. The new GUID will be available in the "Get List of Attachments" call.