Move barycentricCoordinates function to its own file. Modify pointInTriangle2D to use barycentricCoordinates. Fix tests. Move PolygonPipeline.wrapLongitude tests to GeometryPipelineSpec. Add tests for indexing triangle list, fans, and strips.
Add tests for indexing lines.
Add test for computing all attributes when splitting triangles across the IDL.
Add more tests for splitting lines across the IDL.