Replace regexec() calls with calls to a new API stub function ap_regexec().

This solves problems with DSO modules which use the regex library.

Submitted by: Jens-Uwe Mager <jum@helios.de>, Ralf S. Engelschall
Reviewed by: Ralf S. Engelschall


git-svn-id: https://svn.apache.org/repos/asf/httpd/httpd/branches/1.3.x@83226 13f79535-47bb-0310-9956-ffa450edef68