Fix missing space when adding a CSS class
Open page ToC for the page content, and not for the whole toc-root
Replace curly apostrophe ’ with straight single quote '

Excepts on a chrono: 12’57”
Fix double encoding in page ToC

The Makefile `--attribute encoding=utf-8` was not needed,
but I'm sure it won't harm.
Fix link to self page: use # to prevent page reload