Fix readPacket + test script

[remicollet]

Hi,

Thanks for this tool.

I notice issue when trying to get page with long result (ex : phpinfo() page) because of fread buffered behavior.
The first commit fix this.

The second one add a minimal command line tool to test communication with a fastcgi server.

$ ./fcgiget.php /ping
Call: /ping

X-Powered-By: PHP/5.4.9RC1
Content-Type: text/plain
Expires: Thu, 01 Jan 1970 00:00:00 GMT
Cache-Control: no-cache, no-store, must-revalidate, max-age=0

Hello world!

[adoy]

Thanks for your contribution :)