switchover to libxml2 easier.

	* components/help/converters/gnome-db2html2/gdb3html.h:
	* components/help/hyperbola-nav-index.c:
	* components/help/hyperbola-nav-search.c:
	* libnautilus-extensions/nautilus-directory-async.c:
	* libnautilus-extensions/nautilus-directory-metafile.c:
	* libnautilus-extensions/nautilus-directory-metafile.h:
	* libnautilus-extensions/nautilus-directory-private.h:
	* libnautilus-extensions/nautilus-file.c:
	* libnautilus-extensions/nautilus-icon-factory.c:
	* libnautilus-extensions/nautilus-link-set.c:
	* libnautilus-extensions/nautilus-link.c:
	* libnautilus-extensions/nautilus-theme.c:
	* libnautilus-extensions/nautilus-volume-monitor.c:
	* libnautilus-extensions/nautilus-xml-extensions.h:
	* librsvg/rsvg.c:
	* src/nautilus-bookmark-list.c:
	* src/nautilus-bookmark-parsing.c:
	* src/nautilus-bookmark-parsing.h:
	* src/nautilus-link-set-window.c:
	* src/nautilus-property-browser.c:
	* src/nautilus-sidebar.c:
	* src/nautilus-theme-selector.c:
	* src/nautilus-window-menus.c:
	Use the <gnome-xml/> prefix on all includes of gnome-xml headers.
	This is allowed with the version of libxml1 we use now, and
	required for libxml2. Note that we now require the newer libxml1
	version that allows this, because Bonobo requires it.

	* components/services/install/lib/eazel-install-xml-package-list.c:
	(parse_package), (parse_category), (parse_shared),
	(parse_memory_transaction_file), (parse_local_xml_package_list),
	(generate_xml_package_list), (osd_parse_dependency),
	(osd_parse_implementation), (osd_parse_softpkg),
	(osd_parse_shared):
	* components/services/summary/lib/eazel-summary-shared.c:
	(build_services_glist_from_xml), (build_eazel_news_glist_from_xml),
	(build_update_news_glist_from_xml), (parse_summary_xml_file):
	* components/services/trilobite/libtrilobite/helixcode-utils.c:
	(xml_get_value):
	* components/services/trilobite/libtrilobite/trilobite-redirect.c:
	(trilobite_redirect_parse_xml):
	* libnautilus-extensions/nautilus-xml-extensions.c:
	(nautilus_xml_get_children):
	Use xmlChildrenNode instead of childs, as recommended by the
	libxml maintainer for libxml1/libxml2 compatibility.

	* src/nautilus-main.c: (main): Use the LIBXML_TEST_VERSION macro
	as recommended by the libxml maintainer for libxml1/libxml2
	compatibility.

	* components/music/nautilus-music-view.c:
	Added a lot of FIXMEs. Some other rudimentary cleanup.