Remove "timeline" remnants

Remove "timeline" remnants

* doc/orgguide.texi (Timeline): Remove node.
(Top):
(Using TODO states):
(Clocking work time):
(Agenda dispatcher):
(Built-in agenda views):
(Matching tags and properties): Update.
* lisp/org-agenda.el (org-agenda-include-inactive-timestamps):
(org-agenda-format-date):
(org-agenda-format-date-aligned):
(org-agenda-weekend-days):
(org-agenda-prefix-format):
(org-agenda-show-inherited-tags):
(org-agenda-use-tag-inheritance):
(org-agenda-menu):
(org-agenda-max-entries):
(org-agenda-max-todos):
(org-agenda-max-tags):
(org-agenda-max-effort):
(org-agenda-check-type):
(org-agenda-manipulate-query):
(org-agenda-goto-today):
(org-agenda-view-mode-dispatch):
(org-agenda-next-date-line):
(org-agenda-previous-date-line):
(org-agenda-log-mode):
(org-agenda-date-later):
(org-agenda-date-prompt):
(org-agenda-schedule):
(org-agenda-deadline):
(org-agenda-execute-calendar-command):
(org-agenda-goto-calendar):
(org-agenda-convert-date):
(org-agenda-bulk-action):
* lisp/org-mouse.el (org-mouse-agenda-context-menu): Remove reference
  to "timeline".