The wxString saga continues. wxWidgets 3.0 don't have the wxString::FromUTF8(const std::string&) overload, we must use the GUI::from_u8 helper
Also wxWidgets 3.0 don't allow to disable wxString->const char* conversion, so calling show_info(wxWindow*, wxString, const char*) was ambiguous
Several includes moved around
Refactoring of GCode export of color changes, extruder switches etc,
so that the "color change" like extruder switches are applied first
at the Wipe Tower / G-code export, so that adding / removing
an extruder switch at the G-code preview slider does not invalidate
slicing.