Refactored logic in Polygon and Edge into PointGeometry, Line and Geometry.
Fixed bugs found by re-running tests.
Version bump.
Added demo showing difference using a complex line.
Added fromArray() and fromJsts() to Line.
Fixed tests by sorting all polygons created with points out of order.
Updated jsts.
Improved the docs for Polygon.
Merge branch 'feature/lines' into develop