(quail-start-translation): Handle

(quail-start-translation): Handle
switching of the frame in read-key-sequence.
(quail-start-conversion): Likewise.
(quail-show-guidance-buf): Detach quail-guidance-buf from any
windows before setting an appropriate window for it.
(quail-hide-guidance-buf): Use window-minibuffer-p.  Set
quail-guidance-win to nil.
(quail-update-guidance): If quail-guidance-buf is not in the
selected frame, call quail-show-guidance-buf again.