Add "time_since"-information to /api/status

[kaffe.abakus.no/api/status](http://kaffe.abakus.no/api/status) will now return:

    {
      "coffee": {
        "status": true,
        "last_start": "2012-12-12 12:12",
        "time_since":
          "hours": 0,
          "minutes": 0
      }
    }

Also updates the example on [kaffe.abakus.no](http://kaffe.abakus.no).