(auto-save-list-file-prefix): Under MS-DOS, use `.s-'.

(auto-save-list-file-prefix):  Under MS-DOS, use `.s-'.
(normal-top-level): Under MS-DOS, use `make-temp-name' to produce
a unique `auto-save-list-file-name' (PID is not unique enough).
(command-line-1): Delete explicit test for msdos and windowsnt;
test just `window-system'.

(command-line-x-option-alist): Use x-handle-geometry for geometry options.