Remove worker_cpu_affinity directive

worker_cpu_affinity was already commented out and served no purpose as this was the default setting for the 4 worker_processes that we have set. This is a really interesting setting for anyone that wants to know more - http://www.kutukupret.com/2010/11/18/nginx-worker_cpu_affinity/
Tweak some of the WP specific nginx documentation
Improve nginx site example configuration
Update watchr configuration to include new PHP5 config file structure

Even though watchr isn't currently working as intended, we should still account for the possibility.
Remove flags for disabling custom SQL, wp-cli, WordPress stable, and WordPress trunk

Facing up to this being a pretty ridiculous system of disabling certain sections, especially if our primary goal is to provide these as a proper development environment.

Still need to figure out how to handle the unit tests as that takes a *long* time to checkout.
Cleanup non-existing directory from .gitignore
Add GPG public keys for our non standard package sources

Before running `apt-get update`, we should add the public keys for the packages that we are installing from non standard sources via the appended apt sources.list file

Any time a new source is added, we'll likely need to add the key before provisioning will work without error. Our next step will be to remove the `--force-yes` parameter from our apt commands.
Make gpg a bit more quiet when verifying public keys
Use --assume-yes rather than --force-yes with apt commands

Using --force-yes can hide possible problems with provisioning while --assume-yes accomplishes everything that we really need to automate properly.

Thanks @nb!

Closes #78