Translates the path elements in the map using any to_arg helper function.
$map: An array of path arguments; for example, array('node', '5').
$to_arg_functions: An array of helper functions; for example, array(2 => 'menu_tail_to_arg').
function _menu_link_map_translate(&$map, $to_arg_functions) {
$to_arg_functions = unserialize($to_arg_functions);
foreach ($to_arg_functions as $index => $function) {
// Translate place-holders into real values.
$arg = $function(!empty($map[$index]) ? $map[$index] : '', $map, $index);
if (!empty($map[$index]) || isset($arg)) {
$map[$index] = $arg;
}
else {
unset($map[$index]);
}
}
}