High/Low DPI Adapting

The Qt UI would change the size according to the logical DPI of the computer
Only Windows and Linux have been tested. (Should also work on Mac but have not tested).
The function is unfinished.

Fixes #576 
QWidget*, compatible*, inherited*

I also think it will be useful to document what "with dpi" means, what does a class with dpi do, and why and when a contributor would want to use a class with dpi (i.e. use cases).