gettext: downgrade in order to work with older Ubuntu LTS

Summary:
older Ubuntu releases are a little below 0.18.3 plus this makes it
consistent with the rest of our projects.

Reviewers: billiob

Differential Revision: https://phab.enlightenment.org/D1243
improve option names
improve .gitignore and sort it (my OCD is back again!)
i18n: Korean resource(ko.po) initial draft
fix segfault

due to invalid eina_stringshare_del() after pool is freed by
elm_shutdown()