Performance fixes:

* eliminate some copying of sub-parts of the content type in analyze_ct()
* take advantage of the fact that we know the lengths of those sub-parts
  in find_ct() to avoid having to recompute their length for concatenation

The charset handling code needs the same type of optimization eventually.


git-svn-id: https://svn.apache.org/repos/asf/httpd/httpd/trunk@94900 13f79535-47bb-0310-9956-ffa450edef68