Add Load in watts and Load Percentage to webgui settings page

This will display load percentage and the load in watts that the ups is under on the settings page.  If the ups doesn't have the nompower variable it will diplay a red N/A for load.  Could be updated so a user could input  the known nompower for their ups.

![screenshot from 2014-09-06 01 40 45](https://cloud.githubusercontent.com/assets/6558393/4174604/b7e346f4-359a-11e4-820c-28ded2ca9b2a.png)