When generating patterns which are less than a full wave, always
generate the last point correctly.
When extending a full wave to a line, fixup the last point
to the real gyroid position instead of shifting the point.
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.