function getNativeBracketsDirectoryPath() {
        var pathname = decodeURI(window.location.pathname);
        var directory = pathname.substr(0, pathname.lastIndexOf("/"));
        return convertToNativePath(directory);
    }
Returns a native absolute path to the 'brackets' source directory.
Note that this only works when run in brackets/src/index.html, so it does
not work for unit tests (which is run from brackets/test/SpecRunner.html)

WARNING: unlike most paths in Brackets, this path EXCLUDES the trailing "/".
@return {string}