Bug 10818: improve display and translatability of sysprefs OAI-PMH:ConfFile's description

This patch correct english display for OAI-PMH:ConfFile syspref,
and makes it's strings translatable

To test:
1) On Administration > System preferences > Web Services
OAI-PMH:ConfFile syspref doesn't have description before
file box. Text after that box is not translated.
2) Choose your prefered language, xx-YY, update po files
cd misc/translator
perl translate update xx-YY
3) Look into xx-YY-pref.po for any occurence of "YAML", there is none
4) Apply the patch
5) Update po files again
6) Look into xx-YY-pref.po, now there are 2 entries
7) Also reload page from 1) and check for text before
file box.

Signed-off-by: Mark Tompsett <mtompset@hotmail.com>
Signed-off-by: Katrin Fischer <Katrin.Fischer.83@web.de>
Works for me as described, only changes YAML pref file.

Signed-off-by: Galen Charlton <gmc@esilibrary.com>