Port of Angus Johnson's Clipper lib v6.4.2 to haxe 3.1+

• Int64 feature has not been ported yet (as it requires an Int128 not currently available in haxe)
• Tests from the original code have also been ported. They're all passing, except the ones requiring 64bit Ints

^{Screenshot of online js demo (using sui)}

^{Screenshot of C# GuiDemo compiled with VS using haxe generated .NET dll}

A version compiled for usage with Python 2.7 can be found in bin/python27.

(Haxe -> Python 3.x -> Python 2.x (via 3to2))

hxClipper is developed by Giuseppe Di Mauro (azrafe7), porting original code from Angus Johnson, and released under the Boost 1.0 license. See the LICENSE file for details.