[BP] Fix a few markup errors to please pubrules

[tidoust]

Also adjusted encoding issues for some author names (Unicode Normalization Form C should be used), and updated links that yield a 301 permanent redirect to avoid the redirect.

[andrea-perego]

@tidoust , I think there are still some HTML validation issues - see:

https://validator.w3.org/nu/?doc=http%3A%2F%2Fw3c.github.io%2Fsdw%2Fbp%2Findex.html

[tidoust]

@andrea-perego Right but note you're testing the source spec, here, not the generated spec. The errors disappear with the generated spec, except the empty which I had indeed missed and which I had to fix when I prepared the document to publish. I'll create another PR.

[andrea-perego]

Thanks, @tidoust . Yes, I was not actually referring to the warnings.

BTW, please note that, besides the empty <tr>, there are two other errors:

Error: Duplicate attribute class.
At line 4350, column 53

Error: Non-space character in page trailer.
From line 4587, column 1; to line 4587, column 8