Merge r1515245 from trunk:

PR 55447: Elaborate on how a type map foo.html.var can be found when 
requesting foo.html (this was automatic in 1.3)




git-svn-id: https://svn.apache.org/repos/asf/httpd/httpd/branches/2.4.x@1515246 13f79535-47bb-0310-9956-ffa450edef68