Version 1.9.0

Add operators extruding polygons given as points.

• extrudePolygon(): Extrudes a polygon defined by the given points, optionally increasing the size by adding a distance to the outline.
• extrudePolygonBox(): Extrudes a box defined by the given polygon points, optionally increasing the size by adding a distance to the outline.

---

Pull requests:

• Feature/extrude polygon by @jsconan in #118
• Release 1.9.0 by @jsconan in #119

Full Changelog: v1.8.0...v1.9.0