Sync the 'http-dynamic-prop-namespaces' branch with recent trunk changes.
(Merged /subversion/trunk:r1398942-1398962.)

git-svn-id: https://svn.apache.org/repos/asf/subversion/branches/http-dynamic-prop-namespaces@1398963 13f79535-47bb-0310-9956-ffa450edef68