Merge branch 'maint'

* maint:
  maint: add a rule to use gnulib's update-copyright

diff --cc Makefile.am
index 83071f1,76c3e69..323d93d
--- 1/Makefile.am
--- 2/Makefile.am
+++ b/Makefile.am
@@@ -369,3 -783,43 +371,12 @@@ fetch
          echo "See Fetchdir/update.patch for a log of the changes."; \
        exit $$stat
  .PHONY: fetch
 -## Generate release statistics, for the table in automake.texi.
 -## This has to be run in an up to date build tree, but there must
 -## be no temp files nor unused other files lying around!
 -release-stats: ps
 -      $(AM_V_GEN): && \
 -      am=`wc -l < automake` && \
 -      acl=`wc -l < aclocal` && \
 -      pmfiles="lib/Automake/*.pm" && \
 -      if test . != '$(srcdir)'; then pmfiles="$$pmfiles $(srcdir)/lib/Automake/*.pm"; \
 -      else :; fi && \
 -      pm=`cat $$pmfiles | wc -l` && \
 -      dot_am_files=`ls -1 $(srcdir)/lib/am/*.am | grep -v Makefile.am` && \
 -      amf=`echo "$$dot_am_files" | wc -l` && \
 -      aml=`cat $$dot_am_files | wc -l` && \
 -      m4f=`ls -1 $(srcdir)/m4/*.m4 | wc -l` && \
 -      m4l=`cat $(srcdir)/m4/*.m4 | wc -l` && \
 -      doc_text=`cd doc && LC_ALL=C pstops 0 automake.ps unused.ps 2>&1` && \
 -      echo "$$doc_text" && \
 -      rm -f doc/unused.ps && \
 -      doc=`echo "$$doc_text" | sed -n 's/.*Wrote \([1-9][0-9]*\) pages.*/\1/p'` && \
 -      tests="tests/*.test"; \
 -      if test . != '$(srcdir)'; then tests="$$tests $(srcdir)/tests/*.test"; \
 -      else :; fi && \
 -      t=`ls -1 $$tests | wc -l` && \
 -      tgen=`ls -1 $$tests | grep '.-p\.test' | wc -l` && \
 -      today=`date +%Y-%m-%d` && \
 -      echo "add this to the table in doc/automake.texi after verification:" && \
 -      printf '@item %s @tab %-6s @tab %4d @tab %4d @tab %4d @tab %4d %-4s @tab %4d %-4s @tab %3d @tab %d %-4s\n' \
 -                    $$today $(VERSION) $$am    $$acl    $$pm   $$aml "($$amf)" $$m4l "($$m4f)" $$doc $$t "($$tgen)"
 -.PHONY: release-stats
 -
+ 
+ update_copyright_env = \
+   UPDATE_COPYRIGHT_FORCE=1 \
+   UPDATE_COPYRIGHT_USE_INTERVALS=2
+ 
+ .PHONY: update-copyright
+ update-copyright:
+       git ls-files | grep -Ev 'COPYING|INSTALL' \
+         | $(update_copyright_env) xargs $(srcdir)/lib/$@