Update windows instructions for 1.3b6. Move compilation stuff to the end

on the basis that most users will be interested in the pre-compiled
installer. Document the registry key used and how it relates to
command line arguments (-d, -f) and the ServerRoot directive. Show how
to start and stop the Apache service from the command line.


git-svn-id: https://svn.apache.org/repos/asf/httpd/httpd/trunk@81233 13f79535-47bb-0310-9956-ffa450edef68