More TPF-related changes. Among them:

  - Code reorganization to eliminate some TPF #ifdefs
  - Tweaks to the regex code for easier testing
  - Documentation and build updates
  - Notes in the CHANGES file
Submitted by:	David McCreedy <McCreedy@us.ibm.com> and others at IBM


git-svn-id: https://svn.apache.org/repos/asf/httpd/httpd/trunk@83862 13f79535-47bb-0310-9956-ffa450edef68