Prepare our autoconf setup for autoconf 2.14a and for cross-compiling

PR:	6379
Submitted by:	"R�diger" Kuhlmann <Tadu@gmx.de>
Reviewed by:	Ryan Bloom


git-svn-id: https://svn.apache.org/repos/asf/httpd/httpd/trunk@86398 13f79535-47bb-0310-9956-ffa450edef68