steal some code from APR intended to allow you to properly switch

between libtool 1.3 and 1.4+...  newer libtool doesn't have ltconfig,
so having a stray ltconfig around will confuse some of our config
logic

This also fixes cp failure on FreeBSD since ltconfig and ltmain.sh
are installed with 0400 perms, and when buildconf is run a second time
the cp of those files would fail.


git-svn-id: https://svn.apache.org/repos/asf/httpd/httpd/trunk@100178 13f79535-47bb-0310-9956-ffa450edef68