Merge r1369995, r1369999, r1370001 from trunk:

Use apr_pcalloc for rewritemap_entry struct, to avoid uninitialized entries.

PR: 53663
Submitted by: Mikhail T. <mi apache aldan algebra com>


remove now unecessary assignment


Add changes entry for r1369995, r1369999

Submitted by: sf
Reviewed/backported by: jim


git-svn-id: https://svn.apache.org/repos/asf/httpd/httpd/branches/2.4.x@1371208 13f79535-47bb-0310-9956-ffa450edef68