Support glyph path fill rule (non-zero winding / even-odd crossing / etc)

[Azmisov]

The following references 1, 2, 3, 4 indicate that:

• Postscript fonts >= 2.0 use even-odd, < 2.0 use non-zero
• TTF fonts use non-zero
• SVG fonts use the fill rule specified for the path

This library doesn't support SVG outlines, so no problem there I think. The Postscript version (e.g. did outline come from CFF or CFF2 table) could be exposed though. Seems like a simple change.