Handle scroll-error-top-bottom in follow.el and view.el (bug#21893)

Handle scroll-error-top-bottom in follow.el and view.el (bug#21893)

* lisp/follow.el (follow-scroll-up-arg, follow-scroll-up-window):
Use scroll-up-command instead of scroll-up.
(follow-scroll-down-arg, follow-scroll-down-window):
Use scroll-down-command instead of scroll-down.
(follow-scroll-up, follow-scroll-down): Handle scroll-error-top-bottom.

* lisp/view.el (view-scroll-lines): Use scroll-down-command
instead of scroll-down and scroll-up-command instead of scroll-up.
(view-really-at-end): Handle scroll-error-top-bottom.