feature: allow another user to assign/accept a task to you

[carchrae]

i'd love to use the task scheduling feature more, but it is lacking in a few regards. for example, we typically have a fixed schedule with people rotating. right now, that schedule is on our wiki. i would prefer the task system because then people can get reminders when their jobs are coming up.

one big problem right now is i can assign a person, but it stays "red" until the person confirms that they are going to do the job. this has led to extra people offering to do the job, because the original person never bothered to 'accept task'. yes, we could try and train people better, but you know that can be an impossible task.

i therefore suggest two enhancements:

• other people (or an admin role) be given the ability to "Accept Task" on behalf of the user. this is the scheduler/coordinator role.
• if a person is unable to do their job, they can "Unaccept Task" - which means find another person to cover. right now, it seems there is no way to "undo" if you accept a task.