Add "services" to non-servers as "service_subscriptions". Separate method options_documentation() to server_options, platform_options, and site_options.

Create stub methods for Service::server_options(), Service::platform_options() and Service::site_options()

Add Application->getAllServers() and getServerOptions() methods to load all contexts that are servers (to get a list of http servers)

Remove http_platformd_path and http_postd_path from option_documentation(), they are automatically derived.

Load Services into Context classes, and load Configuration classes into Services classes. Rewrite Configuration class from Provision_Config. Run write() method on all Configuration classes on `provision verify` command.