Each application can run with a different user and has its own workers.

Enable user to set the apt/yum module 'state'

Variable to enable / disable php_allow_url_fopen

Enable opcache.revalidate_path setting

Fixes #130 and #48: Tweak and simplify some of the apc and opcache configuration

Fix #120: Introduce variables for FPM user and group.

This is needed otherwise in certain cases one will get
served stale PHP files.

Obtaining php-fpm pool directory status and creating only if the directory does not exist

Users can now set the apt/yum module 'state' to be 'installed, latest, present' etc. This allows a user to test php55, swap a variable to enable the php56 repo, then re-run the ansible play to get different PHP packages.