(proced-grammar-alist): Refiner can be a list (function help-echo)

(proced-grammar-alist): Refiner can be a list (function help-echo)
instead of a cons pair.
(proced-post-display-hook): New variable.
(proced-tree-depth): Renamed from proced-tree-indent.
(proced-mode): Derive mode from special-mode.
(proced-mode-map): Changed accordingly.
(proced, proced-update): Run proced-post-display-hook.
(proced-do-mark-all): Count processes for which mark has been
updated.
(proced-format): Check for ppid attribute.
(proced-process-attributes): Take time and ctime attribute from
system-process-attributes.
(proced-send-signal): Doc fix.  Collect properly the info on
marked processes.  Use fit-window-to-buffer instead of
dired-pop-to-buffer.