Remove cms_langstring for now

git-svn-id: http://svn.cmsmadesimple.org/svn/cmsmadesimple@9355 3d254a34-79dc-0310-9e5f-be208747d8a0
Remove valid_css and valid_html tags

git-svn-id: http://svn.cmsmadesimple.org/svn/cmsmadesimple@9356 3d254a34-79dc-0310-9e5f-be208747d8a0
Remove valid_xhtml tag from default content

git-svn-id: http://svn.cmsmadesimple.org/svn/cmsmadesimple@9357 3d254a34-79dc-0310-9e5f-be208747d8a0
Update changelog

git-svn-id: http://svn.cmsmadesimple.org/svn/cmsmadesimple@9358 3d254a34-79dc-0310-9e5f-be208747d8a0