Fixed some doc typos detected by a user.

Sébastien Santoro (dereckson AT espace-win.org)
sent a bug report about one typo in core.xml
and I executed the aspell tool on the whole file.



git-svn-id: https://svn.apache.org/repos/asf/httpd/httpd/branches/2.4.x@1776711 13f79535-47bb-0310-9956-ffa450edef68