Intended for Factory and 12.3 (adds fresh translations).

Please consider removal of reset-translation-update.sh (probably no more
needed) and removal of Requires: translation-update that adds a package
that contains only doc files (with redundant COPYING). These changes
were not done in my submit.

- Set version to 12.3.
- Added support for auto-generated
translation-update-from-translation-update-upstream tarball
with translation updates and added
translation-update-from-translation-update-upstream-20130214.tar.bz2
- Added support for last minute translations
(translation-update2.tar.bz2).
- Added two supplementary scripts that allow to generate package
list dynamically (translation-update-reset-lang-list.sh,
translation-update-generate-lang-list.sh).
- Added translation-update.rpmlintrc.
- Small improvements of %build and %install to run faster with
cleaner log.

Many of these changes were ported from SLE. (forwarded request 155754 from sbrabec)