(org-agenda-toggle-time-grid): New command.

(org-agenda-toggle-time-grid): New command.
	(org-agenda-use-time-grid, org-agenda-time-grid): New options.
	(org-agenda-add-time-grid-maybe): New function.
	(org-agenda): Call `org-agenda-add-time-grid-maybe'.
	(org-table-create): `dotimes' instead of `mapcar'.
	(org-xor): Simplified implementation.
	(org-agenda): `inhibit-redisplay' turned on.
	(org-agenda-change-all-lines): Use `org-format-agenda-item' to get
	a consistent line after a state change.
	(org-agenda-remove-times-when-in-prefix): New option.
	(org-prefix-has-time): New variable.
	(org-parse-time-string): Optional argument NODEFAULT.
	(org-format-agenda-item): Parse items for time-of-day
	specifications and move these into the prefix if possible.
	(org-agenda-priority): Get current heading, not previous heading
	during agenda remote editing.