Merge r1808008, r1808085 from trunk:

htdigest: prevent buffer overflow when strings in lines are too long.

Reported by: Hanno Böck
PR: 61511



Update CHANGES after r1808008
Submitted by: elukey
Reviewed by: elukey, icing, ylavic


git-svn-id: https://svn.apache.org/repos/asf/httpd/httpd/branches/2.4.x@1808853 13f79535-47bb-0310-9956-ffa450edef68