Merged the C++ port of the GUI Tabs / OptionGroup / Option classes

by @YuSanka, thanks @lordofhyphens for the initial port
of the OptionGroup / Option.

lib/Slic3r.pm

@@ -43,6 +43,7 @@ use FindBin;
 # Let the XS module know where the GUI resources reside.
 set_resources_dir(decode_path($FindBin::Bin) . (($^O eq 'darwin') ? '/../Resources' : '/resources'));
 set_var_dir(resources_dir() . "/icons");
+set_local_dir(resources_dir() . "/localization/");
 
 use Moo 1.003001;