(init_kboard): Initialize it.

(init_kboard): Initialize it.
(syms_of_keyboard): Defvar it.
(read_key_sequence, menu_bar_items):
Check Voverriding_terminal_local_map before Voverriding_local_map.
(command_loop_1): In special handling for commands
that create a prefix arg, don't handle commands that merely
preserve one that was previously created.