build-sys: add NLS support

Add GNU gettext internationalization and localization support.

Signed-off-by: Sami Kerola <kerolasa@iki.fi>

po/.gitignore

@@ -0,0 +1,18 @@
+*.gmo
+boldquot.sed
+en@boldquot.header
+en@quot.header
+insert-header.sin
+Makefile
+Makefile.in
+Makefile.in.in
+Makefile.in.in~
+Makevars.template
+POTFILES
+POTFILES.in
+procps-ng.pot
+quot.sed
+remove-potcdate.sed
+remove-potcdate.sin
+Rules-quot
+stamp-po

po/Makevars

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+# Makefile variables for PO directory in any package using GNU gettext.
+
+# Usually the message domain is the same as the package name.
+DOMAIN = $(PACKAGE)
+
+# These two variables depend on the location of this directory.
+subdir = po
+top_builddir = ..
+
+# These options get passed to xgettext.
+XGETTEXT_OPTIONS = --keyword=_ --keyword=N_ --keyword=P_:1,2
+
+# This is the copyright holder that gets inserted into the header of the
+# $(DOMAIN).pot file.  Set this to the copyright holder of the surrounding
+# package.  (Note that the msgstr strings, extracted from the package's
+# sources, belong to the copyright holder of the package.)  Translators are
+# expected to transfer the copyright for their translations to this person
+# or entity, or to disclaim their copyright.  The empty string stands for
+# the public domain; in this case the translators are expected to disclaim
+# their copyright.
+COPYRIGHT_HOLDER = Free Software Foundation, Inc.
+
+# This is the email address or URL to which the translators shall report
+# bugs in the untranslated strings:
+# - Strings which are not entire sentences, see the maintainer guidelines
+#   in the GNU gettext documentation, section 'Preparing Strings'.
+# - Strings which use unclear terms or require additional context to be
+#   understood.
+# - Strings which make invalid assumptions about notation of date, time or
+#   money.
+# - Pluralisation problems.
+# - Incorrect English spelling.
+# - Incorrect formatting.
+# It can be your email address, or a mailing list address where translators
+# can write to without being subscribed, or the URL of a web page through
+# which the translators can contact you.
+MSGID_BUGS_ADDRESS = procps@freelists.org
+
+# This is the list of locale categories, beyond LC_MESSAGES, for which the
+# message catalogs shall be used.  It is usually empty.
+EXTRA_LOCALE_CATEGORIES =

po/update-potfiles

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+#!/bin/sh
+
+if [ ! -f "po/Makevars" ]; then
+	echo "You must run this script in the top-level directory"
+	exit 1
+fi
+
+find . -name '*.c' |
+	sort |
+	sed 's|^./||
+/^contrib/d' > po/POTFILES.in