backport r1166282 (minus Accept-Ranges: none change) from trunk:

    take care of some MaxRanges feedback:
     * allow "none" to be expressed in config
     * stop accepting confusing/ambiguous "0", start accepting "unlimited".

Reviewed By: covener, wrowe, rpluem



git-svn-id: https://svn.apache.org/repos/asf/httpd/httpd/branches/2.2.x@1166612 13f79535-47bb-0310-9956-ffa450edef68