Put domain names first in site_hosts array

When accessing $_SERVER['SERVER_NAME'] through PHP on Nginx, the first
host in the Nginx conf is used. This makes SERVER_NAME return the
domain name instead of the IP.
Add support for mysql root password
Merge pull request #28 from roots/mysql-passwords

Add support for MySQL root passwords
Add memcached
Merge pull request #29 from roots/memcached

Add memcached
Better development hosts file for Vagrant
Limit some roles to staging and production
Added php5-memcache to php5 setup

Also took the liberty of storing PHP sessions using memcache as well
Merge pull request #35 from FightTheCurrent/master

Added php5-memcache to php5 setup
enable and optimize opcache caching
Merge pull request #44 from FightTheCurrent/feature/opcache

Feature/opcache
Disable Opcache for dev environment
Merge pull request #48 from FightTheCurrent/feature/dev-disable-opcache

Disable Opcache for dev environment
Add fastcgi_param SCRIPT_FILENAME

This could be missing depending on Nginx package versions in Ubuntu so
we're adding it to ensure it's always there.
Always install memcached
Fix plugin name and parentheses.
Merge pull request #51 from c2itllc/readmeupdates

Fix plugin name and parentheses in README.
Tagged playbook roles
Merge pull request #60 from FightTheCurrent/feature/tag-roles

Tagged playbook roles
Improved Vagrant/VirtualBox performance by enabling NFS and increasing host cpu/memory allocation