(previous-input-method): This
variable deleted.
(input-method-history): New variable.
(read-input-method-name): Bind minibuffer-history to
input-method-history.
(activate-input-method): Delete codes handling
previous-input-method. Run hooks in input-method-activate-hook.
(inactivate-input-method): Update input-method-history. Run hooks
in input-method-inactivate-hook.
(select-input-method): Doc-string modified. Use
input-method-history instead of previous-input-method. Set
default-input-method to input-method.
(toggle-input-method): Doc-string modified. Use
input-method-history instead of previous-input-method.
(read-multilingual-string): Bind minibuffer-setup-hook correctly.
(input-method-exit-on-invalid-key): New variable.