maint: Use maintainer-makefile from gnulib

* autogen.sh: Pull GNUmakefile, maint.mk, and dependency scripts in
build-aux.
* cfg.mk (update-copyright-env): Adjust for gettext.
* .x-update-copyright: New file.
* .gitignore: Ignore files brought in by gnulib-tool.

.gitignore

@@ -43,8 +43,14 @@ Makefile
 /gettext-tools/examples/ChangeLog
 /gettext-tools/po/ChangeLog
 
+# Files brought in by gnulib-tool:
+/GNUmakefile
 /build-aux/ar-lib
 /build-aux/git-version-gen
 /build-aux/gitlog-to-changelog
 /build-aux/snippet
 /build-aux/test-driver
+/build-aux/update-copyright
+/build-aux/useless-if-before-free
+/build-aux/vc-list-files
+/maint.mk

.x-update-copyright

@@ -0,0 +1,14 @@
+COPYING$
+COPYING.LIB$
+.*\.po$
+^build-aux/ltmain\.sh$
+^build-aux/texinfo\.tex$
+^m4/lt.*\.m4$
+^m4/libtool\.m4$
+^gettext-runtime/intl/localcharset\.[ch]$
+^gettext-runtime/intl/config\.charset$
+^gettext-runtime/intl/locale\.alias$
+^gettext-tools/doc/gpl\.texi$
+^gettext-tools/doc/lgpl\.texi$
+^gettext-tools/doc/fdl\.texi$
+^gettext-tools/examples/hello-c++-kde/admin/.*$

autogen.sh

@@ -1,5 +1,5 @@
 #!/bin/sh
-# Copyright (C) 2003-2015 Free Software Foundation, Inc.
+# Copyright (C) 2003-2016 Free Software Foundation, Inc.
 #
 # This program is free software: you can redistribute it and/or modify
 # it under the terms of the GNU General Public License as published by
@@ -380,6 +380,11 @@ if ! $skip_gnulib; then
     $GNULIB_TOOL --copy-file tests/init.sh gettext-tools || exit $?
     $GNULIB_TOOL --copy-file build-aux/git-version-gen || exit $?
     $GNULIB_TOOL --copy-file build-aux/gitlog-to-changelog || exit $?
+    $GNULIB_TOOL --copy-file build-aux/update-copyright || exit $?
+    $GNULIB_TOOL --copy-file build-aux/useless-if-before-free || exit $?
+    $GNULIB_TOOL --copy-file build-aux/vc-list-files || exit $?
+    $GNULIB_TOOL --copy-file top/GNUmakefile . || exit $?
+    $GNULIB_TOOL --copy-file top/maint.mk . || exit $?
   fi
 fi
 

cfg.mk

@@ -0,0 +1,5 @@
+SED ?= sed
+
+update-copyright-env = \
+  UPDATE_COPYRIGHT_USE_INTERVALS=1 \
+  UPDATE_COPYRIGHT_MAX_LINE_LENGTH=79