Solve the major underlying problem of content negotation by passing
  mod_negotiation the 'unresolved' parts of the path in a ->notes
  array ap-mime-exceptions-list.

  If mod_mime is given index.html.bad.en it will add index and bad
  to the list (presuming html and en are both defined.)

  mod_negotiation will decide if index and bad are it's fault (the
  user requested index.html.bad[.*]) or if it's a messed up file
  (say .old, .junk, or .bak).

  The next patch to allow any-order negotiation should check each
  of these list elements, so that asking for index.bad in the prior
  example would succeed.  Right now that request would fail because
  .html was recognized, so it's not in the exceptions list.  This
  patch uses a simple strcmp to the given name.

  Also, this patch allows any mod_mime processed file to be served,
  even if the content type cannot be determined (think README.en).
  This is crippled by the client expect headers and omitting the
  default content type.

  PLEASE vet this code carefully.


git-svn-id: https://svn.apache.org/repos/asf/httpd/httpd/trunk@89912 13f79535-47bb-0310-9956-ffa450edef68