Bug 13328: Rename Kurdish translation files

Bug 13328: Rename Kurdish translation files

Kurdish translation files use a variant of Arabic script,
they need to be displayed as RTL.

Currently that is inferred from language dir name after
translation, and that name use the language tag, so we
need to change it from 'ku' to 'ku-Arab'

To test:
1) Translate to Kurdish
(cd misc translator; ./translate install ku)
2) Enable Kurdish on opac/staff
3) Test staff/opac interface, they are displayed as LTR
which is wrong
4) Disable Kurdish language
5) Do a cleanup (git clean -f -d)

5) Apply the patch

6) Translate again
(cd misc translator; ./translate install ku-Arab)
7) Enable again
8) Test again, this time display is correct (LTR)

Signed-off-by: Tomas Cohen Arazi <tomascohen@gmail.com>
Easy to test. Well spotted Bernardo.

Signed-off-by: Katrin Fischer <Katrin.Fischer.83@web.de>
Works as described.