(view-mode-enter): Renamed from view-mode. Callers changed.

(view-mode-enter): Renamed from view-mode.  Callers changed.
Don't create local vars here.  Set view-mode-auto-exit.
Don't change local map--just set view-mode.
(view-mode): New function toggles minor mode in the usual way.
(view-mode-map): Put this on minor-mode-map-alist.
(view-mode-exit): Do the exit actions only if view-mode-auto-exit.
(View-scroll-lines-forward): Exit only if view-scroll-lines-forward.
(view-mode-auto-exit, view-old-buffer-read-only)
(view-old-Helper-return-blurb, view-scroll-size, view-last-regexp)
(view-exit-action, view-return-here, view-exit-position):
Defvar them and make them always-local.