maint: sort .gitignore

Fallout from the new bootstrap.

* .gitignore: Commit sorting done by bootstrap.
* build-aux/.gitignore: Likewise.
* po/.gitignore: Likewise.

.gitignore

+*#*#
+*.#*#
 *.a
 *.o
+*.orig
+*.rej
 *~
 .git
 .git-module-status
+/GNUmakefile
+/maint.mk
 ABOUT-NLS
 COPYING
+ChangeLog
 INSTALL
 Makefile
 Makefile.in
+NEWS
 aclocal.m4
 autom4te.cache
 config.cache
@@ -22,6 +30,7 @@ configure
 coverage
 cscope.files
 cscope.out
+gnulib/
 libtool
 libvirt-*.tar.gz
 libvirt.pc
@@ -34,14 +43,5 @@ results.log
 stamp-h
 stamp-h.in
 stamp-h1
-update.log
 tests/*.log
-/GNUmakefile
-/maint.mk
-gnulib/
-*.orig
-*.rej
-*#*#
-*.#*#
-ChangeLog
-NEWS
+update.log

build-aux/.gitignore

 *
-/link-warning.h
-/mktempd
 /arg-nonnull.h
 /gitlog-to-changelog
+/link-warning.h
+/mktempd
 /useless-if-before-free
 /vc-list-files
+arg-nonnull.h
+config.rpath
+gitlog-to-changelog
+mkinstalldirs
+mktempd
+useless-if-before-free
+vc-list-files
+warn-on-use.h

po/.gitignore

-stamp-po
-remove-potcdate.sin
-quot.sed
-insert-header.sin
 *.gmo
-en@quot.header
-en@boldquot.header
-boldquot.sed
-Rules-quot
-POTFILES
-Makevars.template
-Makefile.in.in
-Makefile.in
 Makefile
-remove-potcdate.sed
+Makefile.in
+Makefile.in.in
 Makevars
+Makevars.template
+POTFILES
+Rules-quot
+boldquot.sed
+en@boldquot.header
+en@quot.header
+insert-header.sed
+insert-header.sin
+quot.sed
+remove-potcdate.sed
+remove-potcdate.sin
+stamp-po