Finish the Configuration cleanup. This basically merges all of the

autoconf scripts that APR provides for other programs into apr_common.m4.
Other programs can then just include that file to get the APR checks that
are required.
Submitted by:	Sascha Schumann <sascha@schumann.cx>


git-svn-id: https://svn.apache.org/repos/asf/httpd/httpd/trunk@85725 13f79535-47bb-0310-9956-ffa450edef68