Merge r463291 from trunk:

So I'm sitting in Rich's talk and think to myself, it's kind
of stupid that DumpIO always logs at Debug, esp when
you consider that it's likely you'll be doing so
in conjunction with SSL... One Big Log is understating
it! :)

Add DumpIOLogLevel to allow one to change the level...

Reviewed by: jim


git-svn-id: https://svn.apache.org/repos/asf/httpd/httpd/branches/2.2.x@486656 13f79535-47bb-0310-9956-ffa450edef68