Don't use Paged.js to layout the print pages unless really needed

Paged.js acts as a polyfill for CSS Paged Media Module, and the Generated Content for Paged Media Module so it needs to be used when these CSS modules are used, which is when:

• generating the page number links for the table of contents
• generating the page header and footer

Considering that:

• Paged.js is a bit slow to generate the print page layout
• and it can enter some infinite loops for some specific content

I think it would be better to not use it unless really needed, i.e. when either the table of contents, or the page header or the page footer are asked for. This way we can be sure that the user always has a way to get the content as PDF, even if that means dropping the table of contents, the header and the footer.