have synced endpoint handle a task existing without a tdone

here's an example of some data I was able to create locally:

        "photos": {
            "at": 1362502629398,
            "data": {
                "class": "personal",
                "frequency": 3600,
                "name": "photos"
            },
            "idr": "task:flickr/photos#85968163%40N04@flickr",
            "service": "flickr",
            "synclet": "photos",
            "tolerance": {
                "averages": [],
                "current": 0
            }
        },

so we need this check, I believe