[O] [RFC] warn time for appointments

[Ivan Kanis]

Hi Bastien,

In bzr emacs there is a new variable called appt-warning-time-regexp. It
contains a string for how many minutes we want to be reminded of an
appointment. 

For example, to be warned 30 minutes in advance of an appointment you
would put the following in the diary file:
   2011/06/01 12:00 Do something ## warntime 30

I would very much like this feature in org. How about we use the same
regexp? We could use this when we call org-agenda-to-appt. A typical
entry would look like this:

* Do something
  <2012-02-04 Sat> warntime 30

What do you think of the specifications? If it's OK with you I will find
the time to do it.

Take care,
-- 
Ivan Kanis
http://kanis.fr

Nothing in life is to be feared. It is only to be understood.
    -- Marie Curie