Merge r1485409:

  Be more clever when allocating memory for log item to be escaped.
  This should be faster and save about 70-100 bytes in the request pool with the default config.

Reviewed by: minfrin, rjung, rpluem


git-svn-id: https://svn.apache.org/repos/asf/httpd/httpd/branches/2.2.x@1510044 13f79535-47bb-0310-9956-ffa450edef68