#442 Please add task dependencies

[Anonymous]

Please could you add a task dependency feature, a bit like Tasknik is planning to do. I think this is one of the biggest missing pieces of functionality in to-do lists currently on the market. It will allow the user to place dependencies between tasks and mask out any tasks that can't currently be done because another needs to be done first. Many thanks.
PS. TaskUnifier is one of the best to-do apps around in my view.