Upgrade version in development branch.
Move CutPolygonByPlane to CutBodyPolygonByPlane.
Add CutPolygonWithPlane experimental code.
Some refactoring near CutPolygonWithPlane.
Some more refactoring near CutPolygonWithPlane.
Add original vertex indices to the result of CutPolygonWithPlane.
Add experimental BSP tree implementation.
Remove CutTriangleWithPlane.
CSG difference tryout.
Boolean operations tryout.
Speed up CutPolygonWithPlane.
Add CSG test.
Add JSVisualTester script.
Keep polygon materials during CSG operations.
Add log to CSG example.
Remove unnecessary alert.
Fix unit test.
Add pure three.js example to test IE11 compatibility.
Some CSG operations refactoring. Do not push everything to BSP tree, only cut with existing polygons.
Fix CSG result polygon directions.