add units to Results.csv headers

[brianlball]

Results.csv headers do not have 'units' in them, like the URBANopt results. example: power(W)
URBANopt users would like this.

[IainMacdonald]

FYI I've added this functionality to our results measure. There is some functionality buried in openstudio itself in a private method that I had to recreate in the measure. Happy to share all the code (it is still on our internal server).