Adding plugin and prop setting for time of day

This allows us to report on the time and day within Omniture. It will allow us to set up segments for weekends, evenings, commuting times, work lunchtimes etc.

![image](https://cloud.githubusercontent.com/assets/796176/3190647/38230678-ecd1-11e3-8b2d-57a1609ae1bb.png)


------------------------------------------------------------

![](http://media.giphy.com/media/12jHPvCe8Nh87C/giphy.gif)
Is this change meant to be in the pull request?