Feature Request: "Include Nested Tasks" Filter

As a user using Quire to manage the backlog of small projects, I want to be able to include tasks nested beneath those selected by a given filter so that I can have a complete view of what is contained within a filtered set.

By making this a filter option instead of default behavior, users can decide whether or not subtasks are included by customizing their filter.

This change would fill a necessary use case for me. Without this, the Tags feature and the In Progress status have very low utility as filters because tasks nested beneath them are not visible and therefor the scope of work is not obvious.