Path import and export

• Added import and export of Sonic Unleashed .path.xml files, it could work with Generations'11 path files too, but I haven't tested it.
• Added an option to import everything BLVL currently can import in one click (no such button for export though)
• Fixed bug that didn't allow to import several .NAVI.xmlbin files in one instance
• Fixed .set.xml not importing if project already had any kind of object (potentially a previous release, but worth mentioning)

Full Changelog: v0.2.2...v0.2.3

Update as usuall, delete old version, close and open blender, and install new one