- add -ipmatch, -str(c)match, -fnmatch, -R operators to ap_expr

- allow lookup function to pre-parse string constant arguments 
  (used for subnet masks so far)
- various bug fixes for binary operators
- do strdup() for error messages created on the stack to avoid corruption


git-svn-id: https://svn.apache.org/repos/asf/httpd/httpd/trunk@1039900 13f79535-47bb-0310-9956-ffa450edef68