Enabled `always_apt_update` for apt.

This seems to be required for a multiple node setup.
Working setup with web server and database server on separate hosts
Added some placeholders for Phabricator configuration
Only grant MySQL access to Phabricator databases
Specify domain instead of hostname
Set `log.access.path` in Phabricator configuration.

The Phabricator access log can provide more detailed information about Phabricator access than normal HTTP access logs (for instance, it can show logged-in users, controllers, and other application data).
Set `metamta.default-address` and `metamta.domain` configuration options.
Set `metamta.single-reply-handler-prefix` configuration so that Phabricator doesn't take up an entire domain.
Enabled `metamta.precedence-bulk`.

If this option is enabled, Phabricator will add a "Precedence: bulk" header to transactional mail (e.g., Differential, Maniphest and Herald notifications).
Enable `celerity.minify` in a production environment.

This option minifies static resources by removing whitespace and comments.
Added TODO
Installed `imagemagick` to resize animation profile pictures.
Installed `pygmentize` for syntax highlighting
Added "MySQL service requires restart after modifying `bind-address`" to TODO
Disabled the default vagrant shared folder