Creates a new blog (site).
This function runs when a user self-registers a new site as well as when a Super Admin creates a new site. Hook to 'wpmu_new_blog' for events that should affect all new sites.
On subdirectory installs, $domain is the same as the main site's domain, and the path is the subdirectory name (eg 'example.com' and '/blog1/'). On subdomain installs, $domain is the new subdomain + root domain (eg 'blog1.example.com'), and $path is '/'.
Uses: domain_exists() , insert_blog() , wp_install_defaults() , add_user_to_blog()
<?php wpmu_create_blog($domain, $path, $title, $user_id, $meta, $site_id); ?>