generate .gitignore files from .cvsignore ones

* Makefile.maint (sync-vcs-ignore-files): New target.
Prompted by a patch from James Morris.
http://thread.gmane.org/gmane.comp.emulators.libvirt/8619/focus=8773
Add all (now-generated) .gitignore files.
* .gitignore: New file.
* build-aux/.gitignore: New file.
* docs/.gitignore: New file.
* docs/devhelp/.gitignore: New file.
* docs/examples/.gitignore: New file.
* docs/examples/python/.gitignore: New file.
* gnulib/lib/.gitignore: New file.
* gnulib/lib/arpa/.gitignore: New file.
* gnulib/lib/netinet/.gitignore: New file.
* gnulib/lib/sys/.gitignore: New file.
* gnulib/tests/.gitignore: New file.
* include/.gitignore: New file.
* include/libvirt/.gitignore: New file.
* po/.gitignore: New file.
* proxy/.gitignore: New file.
* python/.gitignore: New file.
* python/tests/.gitignore: New file.
* qemud/.gitignore: New file.
* src/.gitignore: New file.
* tests/.gitignore: New file.
* tests/confdata/.gitignore: New file.
* tests/sexpr2xmldata/.gitignore: New file.
* tests/virshdata/.gitignore: New file.
* tests/xencapsdata/.gitignore: New file.
* tests/xmconfigdata/.gitignore: New file.
* tests/xml2sexprdata/.gitignore: New file.

po/.gitignore

@@ -0,0 +1,15 @@
+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