Gain/Loss Tracker

Hi,

This script's purpose is to provide a really quick view of gain/loss of a buying price.

As it is my first script, it is not perfect.

You have to select % scale and input your buying price in the options.
I'll continue to work on it to :
- make an auto selection of % scale (if possible)
- render different colors (positive/negative differentiation in relation to the buying price)

Updates 11/10/2017
- default precision set to 8 (for satoshis)