* desktop.cc: added logic to handle to the new dialog and to

* desktop.cc: added logic to handle to the new dialog and to
default the setting for the new checkboxes based on whether the
desktop icon or start menu link already exist.
(desktop_icon): correction to desktop directories for desktop icon
creation.  Additional logic added for Win95 which does not appear
to have Common Directories so if Common selected and null uses
normal directory.
(start_menu): Additional logic added for Win95 which does not
appear to have Common Directories so if Common selected and null
uses normal directory.
(do_desktop_setup): moved the saving of the icon, creation of the
bat file, profile, passwd, Start Menu link and desktop shortcut to
this method from do_desktop.  Made the creation of the desktop
icon and start menu link conditional on settings of new dialog
created for desktop.
* install.cc (do_install): changed next from IDD_S_DESKTOP to
IDD_DESKTOP.
* main.cc (WinMain): changed case IDD_S_DESKTOP to IDD_DESKTOP.
* res.rc: added new resource to create a desktop dialog with 2
checkboxes for creating the desktop icon and start menu link.
* resource.h: changed IDD_S_DESKTOP to IDD_DESKTOP and added two
new controls: IDC_ROOT_MENU and IDC_ROOT_DESKTOP for new dialog.
* state.h: added root_menu and root_desktop for use in dialog.