Number of languages in webpages are wrong.

[Tao Wang]

Hi,

I'm translating the website, I found the number of translation is wrong.

#: features.phtml:83
msgid "Handles internationalized dates and currencies.  The Gnucash
menus and popups have been translated to 21 languages, including
Chinese, Danish, French, German, Hungarian, Italian, Japanese,
Norwegian, Polish, Portuguese, Russian, Spanish, Swedish, Turkish,
Ukrainian, and British English. Documentation is available in English,
French, Portuguese and Spanish."

#: sizing.phtml:17
msgid "GnuCash currently consists of over a third of a million lines
of code spread over more than a thousand files.  It has been
translated into twenty-three languages and credits over 139 authors
and contributors."

The first one said, it's 21 and second said 23, after I count *.po in
po folder, I found 36. So, maybe you just put %s instead of a number,
so it would be easy to make them consistent, especially in multiple
language translations.

And the credits over 139 authors and contributors may also should be
updated, and use %s instead.

-- 
Regards

Tao Wang