[test, html validation] make validator selection somewhat smarter (at least it works properly when content is demoted from xhtml to html, making the XMLDemotingValidator class useless
option_group_changed('port', 'main', 'web')
option_group_changed('query-log-file', 'main', 'web')
option_group_changed('profile', 'main', 'web')
option_group_changed('max-post-length', 'main', 'web')