win32 (from <Someone>)

win32 (from <Someone>)
This patch is an improvement for menu/text dialogs.
This is a code carried over from Windows CE port. It changes
text and menu windows from "system popup" to plain "child"
windows of the main nethack window. Nethack main window can
now be resized/moved/minimized when menu/text window is up.
Menu/text windows will always stay inside the main window and
move along with it.

<Someone>