Embed a web-server that can handle multiple requests at the same time

[GoogleCodeExporter]

Seems like the PHP built-in webserver is not multi-threaded, it
can handle only one request at the same time, this can be a problem
when executing scripts that take a significant amount of time. Take 
for example this scenario:

test1.php
---------
{{{
<?php
sleep(5);
print("test1 finished.");
?>
}}}

test2.php
---------
{{{
<?php
print("test2 finished.");
?>
}}}

Run test1.php & test2.php, you will see that you have to wait five
seconds before test2.php is executed, as test1.php has made the
web-server busy.

The same problem exists when using direct PHP API calls, see Issue 3.

Original issue reported on code.google.com by czarek.t...@gmail.com on 15 Jan 2013 at 5:26