More tweaks to the ordering of conditional request headers.

If If-None-Match is included and fails, then If-Modified-Since
should not be checked.  Likewise for If-Match and If-Unmodified-Since.
This allows the more exact check to be preferred over the less exact check.


git-svn-id: https://svn.apache.org/repos/asf/httpd/httpd/branches/1.3.x@76969 13f79535-47bb-0310-9956-ffa450edef68