**Feature Request**
Brief title for your desired feature:
Make the PCB origin user definable so that it can be set to a convenient point on the PCB to make placement measurements easier.
How would you like the feature to work?
Sometimes it is necessary to make measurements relative to different places on a PCB for different things. Like relative to the centre of the PCB or the front edge of a component (for example, to set the distance from the front mounting face of a potentiometer to the edge of the board).
Why is this feature important to you?
Making measurements is much easier if the PCB origin can be moved to a user defined reference point instead of having to calculate all distances as differences.
Brand new interactions and interfaces. 
Easy to use and quick to get started. 
