Comment 3 for bug 1889000

I did some improvements and variations for footer samples.

Here: https://pastebin.com/KQXkv0ke

You can find 4 variations:
<Current> of <total> / <current section> of <total section>
<Current> of <total> (% read) / <current section> of <total section> (% section read)
<Remaining> of <total> / <remaining section> of <total section>
<Remaining> of <total> (% remaining) / <remaining section> of <total section> (% remaining of section).

(Select the one you want and paste in footer conversion field).

I've built 4 variations for a same book, read with each and personally I prefer second one as it is more natural. For "remaining" variation I need to think "oh, it is remaining, not current".