Description:
------------
It would be _very_ nice to be able to mount an external directory somewhere in the Phar. That way if there are many files that need to be included they don't need to each be Phar::mount()'ed.

Note that all sub files and folders should also be in directory listings and available through the Web. Bugs 53809 and 53801.

The directory structure should be as follows for the test below:

make.php = In the test script below
list.php = In the test script below
ext/page1.html = <p>Page 1</p>
ext/page2.html = <p>Page 2</p>

Test script:
---------------
<?php
// make.php

try {
    $p = new Phar('test.phar');
    $p->addFile('list.php');
    $p->setStub('<?php
Phar::interceptFileFuncs();
Phar::webPhar("test.phar", "list.php");
Phar::mount(__DIR__ . "/ext/", "ext/");
__HALT_COMPILER();');
    echo 'Done making test.phar';
} catch (Exception $e) {
    echo 'Exception caught: ' . $e->getMessage();
}
?>


<?php
// list.php

$path = Phar::running() . '/ext';
echo "Path: $path<br>\r\n";
echo 'Exists: ' . (file_exists($path) ? 'Yes' : 'No') . "<br>\r\n";
echo "Listing...<br>\r\n";
foreach (new DirectoryIterator($path) as $file) {
    if ($file->isDot()) continue;
    echo $file->getFilename() . "<br>\r\n";
}
echo "...done listing<br>\r\n";
?>

Expected result:
----------------
Visiting: make.php
Done making test.phar

Visiting: test.phar/list.php
Path: phar://test.phar/ext
Exists: Yes
Listing...
page1.html
page2.html
...done listing

Visiting: test.phar/ext/page1.html
Page 1

Actual result:
--------------
Visiting: make.php
Done making test.phar

Visiting: test.phar/list.php
Path: phar://test.phar/ext
Exists: No
Listing...

Visiting: test.phar/ext/page1.html
404 - File /ext/page1.html Not Found