ADD: lbs/oz, grams

[maxihatop]

This is small extension, for print out more detailed info from my own scale, always returns "oz" only.

[erjiang]

Thanks for the proposal! The units are chosen by the scale but I can see the utility of being able to convert oz to g or calculate lbs-oz. Since new argument-parsing code just landed, I will think about how to best make this a feature.