(Vw32_phantom_key_code): New variable.

(Vw32_phantom_key_code): New variable.
(Qhyper, Qsuper, Qmeta, Qalt, Qctrl, Qcontrol, Qshift): New
variables.
(syms_of_w32fns): Init and register them.
(reset_modifiers): Use a more precise test for whether Emacs has
keyboard focus.  Synchronize state of all keys that can be used as
modifiers, to overcome problems arising from hot-keys.
(w32_key_to_modifier): Be careful not to call intern() to avoid
requiring thread synchronization.
(w32_msg_pump): Handle new WM_EMACS_TOGGLE_LOCK_KEY message.
(w32_wnd_proc): Ensure lock key indicator lights are updated
promptly on Windows 9x, by passing key events on to the system.
(w32_wnd_proc): Use Vw32_phantom_key_code to stop system
responding to Windows key events when not wanted.
(w32_wnd_proc): Undo the mapping of Ctrl-Pause into cancel and
Ctrl-NumLock into pause by the system.
(w32_wnd_proc): Don't translate key combinations containing any
modifiers other than shift (and capslock).
(w32_wnd_proc): Reset modifier key states when receiving focus (we
can't determine the key states until we have keyboard focus).
(Fw32_toggle_lock_key): New function.
(syms_of_w32fns): Defsubr it.