Reimplement ThreadStackSize to behave as on unix for any

Windows 2003/2008 (XP/Vista) servers.  Virtual allocations
will only consume pages once referenced, while the page
alignment will vary by ThreadStackSize setting so that the
maximum number of threads and minimum stack VM profile will
be wasted.

git-svn-id: https://svn.apache.org/repos/asf/httpd/httpd/trunk@699481 13f79535-47bb-0310-9956-ffa450edef68