includes deletion of varialble ethio-mode, variable
ethio-mode-map, and function ethio-mode.
(exit-ethiopic-environment-data): New variable.
(setup-ethiopic-environment): Recode information of changed key
bindings in exit-ethiopic-environment-data. Add
ethio-select-a-translation to quail-mode-hook.
(exit-ethiopic-environment): New function.
(ethio-find-file): Don't check ethio-mode.
(ethio-write-file): Likewise.
keys in global-map, don't add a hook to rmail-mode-hook and
mail-mode-hook.
(ethio-mode): New buffer local variable.
(ethio-mode-map): New variable.
(ethio-mode): New function.
(ethio-sera-to-fidel-mail-or-marker): New function.
(ethio-fidel-to-sera-mail-or-marker): New function.
(ethio-find-file): Do nothing if not in ethio-mode.
(ethio-write-file): Likewise.
(ethio-prefer-ascii-space): Moved from leim/quail/ethiopic.el.
(ethio-toggle-space): Likewise.
(ethio-insert-space): Likewise.
(ethio-insert-ethio-space): Likewise.
(ethio-prefer-ascii-punctuation): Likewise.
(ethio-toggle-punctuation): Likewise.
(ethio-gemination): Likewise.