https://github.com/prusa3d/Slic3r/issues/597
The "Send to OctoPrint" function will now send the file name encoded
in UTF-8, so the file name will not get mangled.
The C++ Slic3r::encode_path() function was returning a string to Perl,
which was marked as UTF-8. This has been fixed, now encode_path() returns
a plain Perl string.
Added path_to_filename, path_to_stem, path_to_extension, path_to_parent_path
Perl wrappers to boost::filesystem::path splitting functionality
to be able to split UTF-8 encoded files on Windows correctly.