Approximate number of search results

The number of results listed on the search results page is often an
estimate when working with a large set. Let's add the word "about" to
reflect the fact that it is indeed an estimate.

At the same time, I moved the <strong> tags out of the code, adding a CSS
class in its place, moved the HTML tags out of the translatable
string (as recommended by Pasi Kallinen), and fixed a typo in the
stylesheet.

Signed-off-by: Kathy Lussier <klussier@masslnc.org>
Signed-off-by: Mike Rylander <mrylander@gmail.com>