Hi,

This patch fixes a minor issue with proced buffers.  Previously, the window
position would be set to the start of the buffer when a proced buffer was
updated and it was not displayed in the selected window.  To reproduce:

(require 'proced)
(setq-default proceed-auto-update-flag t)
(M-x proced)

Move down to the next process, then change to a different window, and wait
a bit.  You should see the point in the proced buffer move back to the
beginning of the buffer. A similar issue occurs when the proced buffer is
not displayed in any window.

This patch addresses this by setting the window point (if applicable)
whenever a proced buffer is updated, and the second issue by not updating a
proced buffer if it is not displayed in any window.

I tried to add a test for this, but for example this:

(ert-deftest proced-update-preserves-point-test ()
  (proced--within-buffer
   'medium
   'user
   (proced--move-to-column "PID")
   (let ((point (window-point))
         (window (split-window)))
     (select-window window)
     (bury-buffer)
     (with-current-buffer "*Proced*"
       (proced-update t t))
     (switch-to-buffer "*Proced*")
     (should (= point (window-point))))))

passes even without this patch (though if I step through it with
edebug-defun it fails as expected).

Thanks, Laurence