function handleShowInOS() {
        var entry = ProjectManager.getSelectedItem();
        if (entry) {
            brackets.app.showOSFolder(entry.fullPath, function (err) {
                if (err) {
                    console.error("Error showing '" + entry.fullPath + "' in OS folder:", err);
                }
            });
        }
    }
Show the selected sidebar (tree or workingset) item in Finder/Explorer