Changes in SupportMaterial.cpp, TriangleMesh.cpp and 01_trianglemesh.t are yet to be merged. WIP: Refactoring of layer height editing. Removed layer_height_ranges from PrintObject, as the Print/PrintObject now hold their copies of Model/ModelObject.
(rely on -Ilibslic3r set correctly) for the slic3r project.
The XS was left only for the unit / integration tests, and it links libslic3r only. No wxWidgets are allowed to be used from Perl starting from now.