Update sitemap.xml - update test files' path - change daily to monthly - remove forum.php links - remove lastmod
Update sitemap.xml
- update test files' path
- change daily to monthly
- remove forum.php links
- remove lastmod

Review URL: http://codereview.appspot.com/4550114
liunian/compatibility-detector,liunian/compatibility-detector,liunian/compatibility-detector