Add support for -f option
Add support for -f option

Now it's possible to use php.php as a test executable for run-tests.php

ircmaxell/PHPPHP,PlethoraLabs/PHPPHP,asgrim/PHPPHP,PlethoraLabs/PHPPHP,asgrim/PHPPHP,srsbiz/PHPPHP,srsbiz/PHPPHP,ircmaxell/PHPPHP