Update to gnome-themes-extra-3.28. This required a complete rename due to upstream
changes, as well as modifications to a few pages. I have verified that it renders,
but Bruce should probably check the currency script for necessary changes. Thanks to
Xi for reporting that it changed.
git-svn-id: svn://svn.linuxfromscratch.org/BLFS/trunk/BOOK@20610 af4574ff-66df-0310-9fd7-8a98e5e911e0