We need to update the tag builder attributes for 4.8. There have been a few changes that impact them. And while we're there, we should probably see what can be done about global attributes.

Most of them have the same default value, but one or two require different ones so it might just be a case of writing a globalAtts() function that takes an optional array of default values, and calling that in every tag to merge it with the $atts array.

Any better ideas?

See #1193 for previous musings on this issue.