New "Visible Hairlines" display mode makes sure hairlines are never too thin to see

New "Visible Hairlines" option in View->Display Mode which make sure all strokes are at least 0.5px thick, even when zoomed out.

This is particularly useful for CNC machines like laser cutters and vinyl cutters, where you define cuts with 0.001" hairlines.

This works by testing if the rendered lines will be smaller than 0.5px on screen and scales them up.

The only thing I'm unsure of is whether it would be better to make this a checkbox in the View menu, so your preference can be remembered between sessions.