make the configure script detect that it is running on a Windows platform, and report...

make the configure script detect that it is running on a Windows platform, and report that information so that menuselect can use it (all information that is used to decide whether to build modules or not must be fed to menuselect so the user knows what will be built and why... don't make module build decisions in the makefiles, please)

git-svn-id: https://origsvn.digium.com/svn/asterisk/trunk@93211 65c4cc65-6c06-0410-ace0-fbb531ad65f3