Description:
------------
On the documentaiton page of php.ini, it states:

" Since PHP 5.1.0, it is possible to refer to existing .ini variables from within .ini files. Example: open_basedir = ${open_basedir} ":/new/dir"."

This does not seem to work in 5.1 for parse_ini_file.

Also, it appears there is no way to reference sections, e.g.,

baz = ${section.foo}

That would be nice. Very nice, in fact (regardless of syntax required).

Reproduce code:
---------------
--- file.ini ---
[Test]
foo = bar
baz = ${foo}

--- test.php ---
<?php

$ini = parse_ini_file( "file.ini", true );

var_dump( $ini );

?>

Expected result:
----------------
array(1) {
  ["Test"]=>
  array(2) {
    ["foo"]=>
    string(3) "bar"
    ["baz"]=>
    string(3) "bar"
  }
}

Actual result:
--------------
array(1) {
  ["Test"]=>
  array(2) {
    ["foo"]=>
    string(3) "bar"
    ["baz"]=>
    string(0) ""
  }
}