Lipstick shows wrong duration when job runs over days

Here is an example-

![screen shot 2014-07-28 at 2 47 41 pm 1](https://cloud.githubusercontent.com/assets/179618/3785142/0877f41c-19c0-11e4-98a7-6b396cb583fd.png)
As can be seen, the job ran over 17 hours (from 25th to 26th), but the duration shows 5 hours.

I identified the following code as culprit-
var duration = moment().startOf("day").add("ms", (mrJobInfo.runData.finishTime - mrJobInfo.runData.startTime))

This assumes that all the job starts and finishes on the same day, which cannot be always true.