sitemapper update

The Google sitemap protocol was recently adopted by Yahoo and Microsoft and
made a common standard. This patch changes the XML namespace URL to the new
sitmaps.org site and ups the version to 0.9

Pinging of Yahoo and Microsoft was added to the existing Google ping. The
microsoft ping currently fails with a "Bad format" error for unknown reason.
This will hopefully change when either Microsoft fixes their URL or releases
some documentation.

darcs-hash:20061117150030-7ad00-0fac1cba07926c3ffe687a8cbaf465e8de3abcd7.gz