(quail-conversion-keymap): New binding

(quail-conversion-keymap): New binding
for quail-conversion-delete-tail.
(quail-input-method): Suppress input method if
overriding-terminal-local-map or overriding-local-map is non-nil.
Erase contents of quail-guidance-buf.  Run the hook
input-method-after-insert-chunk-hook.
(quail-start-translation): Get the original event list by
listify-key-sequence.  Setup last-command and this-command
(quail-start-conversion): Likewise.
(quail-conversion-beginning-of-region): Set quail-translating to
nil.
(quail-conversion-end-of-region, quail-conversion-delete-char):
Likewise.
(quail-conversion-delete-tail): New function.
(quail-no-conversion): Don' run the hook
input-method-after-insert-chunk-hook.