Improve future detection when reading dates

Improve future detection when reading dates

PT writes:

> [Orgmode] org-read-date-prefer-future 'time doesn't always prefer future
>
> This is a very useful setting, because it allows the user to
> quickly schedule a task into the future by simply entering the
> time, but it doesn't always do the right thing.
>
> Suppose I scheduled a task to 1pm, but I didn't have time to deal
> with it during the day. It's 5pm now. If I want to reschedule the task to
> tomorrow 10am then I can write simply 10am to the time prompt and
> it puts the task correctly to tomorrow 10am. However, if I want
> to reschedule it to tomorrow 2pm then I can't write simply 2pm,
> because then it schedules the task at 2pm today (which is past
> already, since it's 5 pm).
>
> The problem is the feature uses the task's own scheduled time to
> determine if a time is in the past, instead of the current time.
>
>
> It's Org-mode version 6.33