(org-tags-match-list-sublevels): New option.
(org-open-at-point): implement tag searches as links
(org-fit-agenda-window, org-get-buffer-tags, org-get-tags)
(org-make-tags-matcher, org-scan-tags, org-activate-tags): New
functions
(org-tags-sparse-tree, org-tags-view, org-set-tags)
(org-agenda-dispatch): New commands.
(org-use-tag-inheritance, org-tags-column): New options.
(org-tab-follows-link, org-return-follows-link): New options.
(org-tags): New customize group.
(org-start-icalendar-file): Get local time zone.
(org-tags-completion-function): New function.
(org-set-font-lock-defaults): make sure links will also
be highlighted inside headlines.