Merge branch 'ar/i18n-no-gettext'

* ar/i18n-no-gettext: i18n: Do not force USE_GETTEXT_SCHEME=fallthrough on NO_GETTEXT i18n: Make NO_GETTEXT imply fallthrough scheme in shell l10n add a Makefile switch to avoid gettext translation in shell scripts git-sh-i18n: restructure the logic to compute gettext.sh scheme