Add support for Cacti under Ubuntu

 * Update server recipe for Ubuntu package names
 * Update spine recipe for Ubuntu package names
 * Change path for running initial SQL file on Ubuntu
 * Update Apache config template to use conf_dir attribute instead of hard coding the path
 * Update server recipe to use user/group attributes instead of hard coding them
 * Add more attributes for SSL support
 * Add an attribute for the Apache DocumentRoot
 * Ubuntu-specific cacti.conf file
 * Make crontab configurable (some people may want a higher granularity than every 5 minutes)
 * Fix cron path on Ubuntu