Create both auto-group and normal selector versions of :ancestor-with-todo

My understanding is that `:ancestor-with-todo` was originally an auto group selector, then temporarily changed to a normal selector, and then changed back into an auto group. This is described in #281 .

I find both versions very useful so I was wondering if both be could be implemented at the same time?

Perhaps the group selector could be changed to `:auto-ancestor-with-todo`, and `:ancestor-with-todo` could then be made the normal selector?

Or the normal selector could just be called `:ancestor`, as a sort of opposite to the `children` selector.

The code for the normal selector version already exists, so I think this might be a relatively easy thing to implement. What are your thoughts?