Clipper full changelog

Released on 27 February 2017 (Rev 512)
Several minor bug fixes: #152 #160 #161 #162

Numerous generally minor bugfixes.

Bugfix in ClipperOffset.Execute where the Polytree.IsHole property was returning incorrect values with negative offsets
Very minor improvement to join rounding in ClipperOffset
Fixed CPP OpenGL demo.

Fixed potential endless loop condition when adding open paths to Clipper.
Fixed missing implementation of SimplifyPolygon function in C++ code.
Fixed incorrect upper range constant for polygon coordinates in Delphi code.
Added PointInPolygon function.
Overloaded MinkowskiSum function to accommodate multi-contour paths.

Fixed a couple of bugs affecting open paths that could raise unhandled exceptions.

Added: Open path (polyline) clipping. A new 'Curves' demo application showcases this (see the 'Curves' directory).
Update: Major improvement in the merging of shared/collinear edges in clip solutions (see Execute).
Added: The IntPoint structure now has an optional 'Z' member. (See the precompiler directive use_xyz.)
Added: Users can now force Clipper to use 32bit integers (via the precompiler directive use_int32) instead of using 64bit integers.
Modified: To accommodate open paths, the Polygon and Polygons structures have been renamed Path and Paths respectively. The AddPolygon and AddPolygons methods of the ClipperBase class have been renamed AddPath and AddPaths respectively. Several other functions have been similarly renamed.
Modified: The PolyNode Class has a new IsOpen property.
Modified: The Clipper class has a new ZFillFunction property.
Added: MinkowskiSum and MinkowskiDiff functions added.
Added: Several other new functions have been added including

· BugFix: CleanPolygon function was buggy.
· Changed: The behavior of the 'miter' JoinType has been changed so that when squaring occurs, it's no longer extended up to the miter limit but is squared off at exactly 'delta' units. (This improves the look of mitering with larger limits at acute angles.)
· Added: New OffsetPolyLines function
· Update: Minor code refactoring and optimisations

· Added: ForceSimple property to Clipper class
· Update: Minor code optimizations and trivial bug fixes
· Update: Improved documentation

· Update: CleanPolygon function enhanced.
· Update: Documentation improved.

· Bugfix: Minor bugfixes.
· Update: Documentation significantly improved.