Merge r1685345, r1685347, r1685349, r1685350 from trunk:

Follow up to r1684513: allow spaces before and after chunk-size.
Slightly modified version of trawick's proposal.

Follow up to r1685345: don't accept spaces *before* the chunk-size.

Follow up to r1685345: CHANGES entry.

Follow up to r1685349: remove a tab.
Submitted by: ylavic
Reviewed/backported by: jim


git-svn-id: https://svn.apache.org/repos/asf/httpd/httpd/branches/2.4.x@1686271 13f79535-47bb-0310-9956-ffa450edef68