Merge r1554276, r1554281, r1555555 from trunk:

    digest auth is only marginally more secure than basic auth.
    Adjust the docs to today's reality.

    mention insecure password storage as pointed out by Graham

    axe one more case of digest auth being described as secure



git-svn-id: https://svn.apache.org/repos/asf/httpd/httpd/branches/2.2.x@1555566 13f79535-47bb-0310-9956-ffa450edef68