org-agenda: Handle case of heading w/ date but no keyword
* lisp/org-agenda.el (org-agenda-highlight-todo): Handle the case of a
heading that has a date but no todo keyword.
This is a fix for the args-out-of-range bug discussed in these threads:
http://thread.gmane.org/gmane.emacs.orgmode/52621
http://thread.gmane.org/gmane.emacs.orgmode/52793
http://thread.gmane.org/gmane.emacs.orgmode/52786
http://thread.gmane.org/gmane.emacs.orgmode/52810
The discussions involved Ilya Shlyakhter, James Atwood, Nick Dokos,
and myself, and the subject headers are:
bug report: agenda timeline crashes
Bug report: weekly agenda and blank, timestamped headers
org-agenda-list (from git) giving "args-out-of-range error"
TINYCHANGE