Problem if site_url is not root

Hi there,

I just stumbled over your plugin and noticed there’s a small problem if one has a site with anything other than the root url (/) as site_url:

plugin.php:

121 '/wp-admin/post.php?post=' . $post_id . '&action=edit',

should be:

121 get_site_url() . '/wp-admin/post.php?post=' . $post_id . '&action=edit',

The same here:

333 get_site_url() . '/wp-admin/post.php?post=' . $post_id . '&action=edit',

345 get_site_url() . '/wp-admin/post-new.php?post_type=wpf_post_it',

Maybe there are other such cases that I didn’t find yet.