Setup Apache 2.4 and Php FPM with mod proxy fcgi on Ubuntu 13.10

The module mod_proxy_fcgi is a new one and it allows apache to connect to/forward requests to an external fastcgi process manager like php fpm. This allows for a complete separation between the running of php scripts and Apache. Earlier we had to use modules like mod_fcgid and mod_fastcgi which all had some limitations. Mod_fcgid for example did not properly utilise the process management capability of php-cgi whereas mod_fastcgi is a third party module.