Support modifiers in effort durations (was: Re: Does Effort support hours only?)

Support modifiers in effort durations (was: Re: Does Effort support hours only?)

Luke Crook wrote:
> Is it possible to specify estimated effort in something other
> than hours (0.5, or 0:30)?

> For example 1w, 1m, 2d etc?

Here's a cleaned up patch that allows user-specified modifiers
for effort strings.  The new variable `org-effort-durations'
lists modifiers, and their mapping to minutes (words, as well as
single-letter modifiers, are supported).  The default value is:

(("h" . 60)
 ("d" . 480) ; 8 hours
 ("w" . 2400) ; five days
 ("m" . 9600) ; 4 weeks
 ("y" . 96000)) ; 40 weeks

But you can change this.

Old effort strings (HH:MM) are still interpreted correctly.  See
the docstrings of `org-effort-durations' and
`org-duration-string-to-minutes' for more details.

>From a0e24b14755eb4087d9c47bb4eea11eb9151efcf Mon Sep 17 00:00:00 2001
From: Lawrence Mitchell <wence@gmx.li>
Date: Fri, 18 Feb 2011 11:01:46 +0000
Subject: [PATCH] Allow human-readable effort durations
To: emacs-orgmode@gnu.org

* lisp/org.el (org-effort-durations): New variable.
* lisp/org.el (org-duration-string-to-minutes): New function.
* lisp/org-agenda.el (org-agenda-filter-effort-form)
(org-format-agenda-item): Use it.
* lisp/org-clock.el (org-clock-notify-once-if-expired)
(org-clock-modify-effort-estimate, org-clock-get-clock-string): Use it.

Specifying large effort durations in hours and minutes is difficult.
Is 130:25 more than two weeks effort?  More than three?  This patch
allows specification of an effort duration as a friendly string.  For
example 2w 5d is two weeks and five days of effort.  Existing H:MM
entries will still be recognised correctly.