[web, formatting] move Interval data type display logic from final view to printable_value (closes #1984742)
also, fix implementation so that negative time delta are properly considered
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')