Change to org-agenda-time-grid in Org 9.1

Another small one that others might be searching for. The upgrade to Org 9.1 included a change to the arguments in org-agenda-time-grid, adding a new one and rearranging them a bit. This was my previous setting (from Bernt Hansen’s config):

(setq org-agenda-time-grid (quote ((daily today remove-match)
                                   #("----------------" 0 16 (org-heading t))
                                   (0900 1100 1300 1500 1700))))

And now it’s this:

(setq org-agenda-time-grid (quote ((daily today remove-match)
                                   (0900 1100 1300 1500 1700)
                                   "      " "................")))

It doesn’t seem necessary to insert org-heading into the last string anymore; it’s doing that on its own, even though the docstring for the variable doesn’t mention that. I changed those two strings just for style purposes. The first, shorter string comes after the time in the scheduler, and spaces look better there.