Add ModMimeUsePathInfo directive.

This directive allows mod_mime to lookup extension information for content
served via Location blocks so that content-type, filters, etc can be
applied to non-file content.

(I wouldn't be shocked if we end up changing the directive name.)


git-svn-id: https://svn.apache.org/repos/asf/httpd/httpd/trunk@96644 13f79535-47bb-0310-9956-ffa450edef68