configure: add basic support to build with MinGW/MSYS, from trunk r422182 by pquerna

2.2.x patch submitted by: fuankg
Reviewed by: wrowe, trawick


git-svn-id: https://svn.apache.org/repos/asf/httpd/httpd/branches/2.2.x@1090795 13f79535-47bb-0310-9956-ffa450edef68