Permit --with-apr=/path/to/apr alone, where the default path will

Permit --with-apr=/path/to/apr alone, where the default path will
be handled by replacing all /apr path segments with /apr-util
(or /aprutil) to handle nearly any developer's path scheme.  One
rare exception would be /asf/srcs/aprutil/trunk/apr-util or similar
where both /aprutil and /apr-util path segments exist.

So for example --with-apr=../apr-1.3 would find either ../apr-util-1.3
or ../aprutil-1.3 before looking for srclib/apr-util or ../apr-util.

These refer to source trees.  httpd ./configure deserves a similar
feature to use --with-apr= for an installed apr-util lib tree.

git-svn-id: https://svn.apache.org/repos/asf/httpd/httpd/trunk@687939 13f79535-47bb-0310-9956-ffa450edef68